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Analytical Chemistry Presents with State-of-the-Art Molecular Recognition and Interaction

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Analytical Chemistry".

Deadline for manuscript submissions: closed (31 January 2024) | Viewed by 11808

Special Issue Editor

Special Issue Information

Dear Colleagues,

In 21st century, in order to tackle the great challenges of food security, public health and environment preservation, accompanied by the continuous development of industrialization, urbanization and globalization, both analytical and bioanalytical chemistry with the molecular science of interaction and recognition play important roles and have shown obvious evolution in various fields (e.g., geological material analysis, archaeological research, forensic detection, agricultural and industrial production, environmental preservation and renovation, food safety and authenticity, clinical diagnosis and disease control, aerospace medical research and space exploration) and achieved remarkable advances in recent years, as evidenced by many state-of-the-art research practices.

This Special Issue will include both well-drafted review and research manuscripts related to highly efficient sample pretreatment/separation and precise analyte analysis/identification with or without advanced materials (e.g., functional nanomaterials or hybrid/frame assembled materials for significant sensitivity and selectivity enhancement in analytical or bioanalytical chemistry). The analytical strategies of interest include but are not limited to elemental mapping or elemental speciation analysis, direct-analysis mass spectrometry or mass spectrometry with ambient ionization, miniaturized mass spectrometry, mass spectrometric imaging or visualization, native mass spectrometry, isotopic mass spectrometry, multi-dimensional nuclear magnetic resonance spectroscopy (NMR), high-performance gas/liquid chromatographic technologies hyphenated with high-resolution mass spectrometry, targeted or non-targeted proteomic/metabonomic profiling, lateral-flow antibody- or aptamer-based immunochromatographic rapid assay, microfluidic/nanofluidic analysis, lab-on-a-chip (LOC) devices or micro total analysis (μTAS) systems, portable spectrometry and hyper- or super-spectrometry with rational chemometric or artificial intelligence algorithms, isothermal amplification or amplification-free molecular detection technologies, gene microarrays and modern high-throughput sequencing schemes, and highly sensitive analytical sensors (e.g., electrochemical or optical sensors, sensor arrays, nanowire sensors, CRISPR/Cas-based biosensors and other label-free sensors based on novel biophysical or biochemical principles).

This Special Issue will consider inorganic and organic elements, biomarkers for medical diagnosis, pharmaceuticals with impurities for disease control, doping drugs, and residual agrochemicals (e.g., pesticide or veterinary drug residues), natural toxins, environmental contaminants (e.g., persistent organic pollutants (POPs) and endocrine-disrupting compounds (EDCs)), pathogenic food contaminants, illegal food adulterants, food allergens, GMOs, and microbial pathogens (e.g., bacteria, fungi, SARS-CoV-2 and other emerging infectious viruses).

In addition, to better ensure the quality of analysis and risk management, analytically related research on proficiency test practices, preparations of reference materials with material certification or value assignment efforts, and risk analysis/assessment attempts for certain deleterious analytes or metabolites are also welcome.

The aim of this Special Issue is to not only present a general overview of the most advanced analytical schemes for analyzing and identifying analyte molecules or risk factors, but also to outline the current research trends in various analytical domains. The Special Issue will help to acquaint the molecular science community with cutting-edge analytical principles and approaches thereof.

Prof. Dr. Yiyang Dong
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • ambient ionization
  • visualization
  • mass profiling
  • chromatography
  • microfluidics
  • biosensors
  • omics research
  • aptamers

Related Special Issue

Published Papers (9 papers)

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Research

Jump to: Review

14 pages, 3299 KiB  
Article
Design and Validation of a Short Novel Estradiol Aptamer and Exploration of Its Application in Sensor Technology
by Hongyan Jin, Yan Cheng, Fanli Kong, He Huang, Zhenjun Yang, Xinyi Wang, Xinxia Cai, Jinping Luo and Tao Ming
Molecules 2024, 29(2), 535; https://doi.org/10.3390/molecules29020535 - 22 Jan 2024
Viewed by 643
Abstract
The specific and sensitive detection of 17β-estradiol (E2) is critical for diagnosing and treating numerous diseases, and aptamers have emerged as promising recognition probes for developing detection platforms. However, traditional long-sequence E2 aptamers have demonstrated limited clinical performance due to redundant structures that [...] Read more.
The specific and sensitive detection of 17β-estradiol (E2) is critical for diagnosing and treating numerous diseases, and aptamers have emerged as promising recognition probes for developing detection platforms. However, traditional long-sequence E2 aptamers have demonstrated limited clinical performance due to redundant structures that can affect their stability and recognition ability. There is thus an urgent need to further optimize the structure of the aptamer to build an effective detection platform for E2. In this work, we have designed a novel short aptamer that retains the key binding structure of traditional aptamers to E2 while eliminating the redundant structures. The proposed aptamer was evaluated for its binding properties using microscale thermophoresis, a gold nanoparticle-based colorimetric method, and electrochemical assays. Our results demonstrate that the proposed aptamer has excellent specific recognition ability for E2 and a high affinity with a dissociation constant of 92 nM. Moreover, the aptamer shows great potential as a recognition probe for constructing a highly specific and sensitive clinical estradiol detection platform. The aptamer-based electrochemical sensor enabled the detection of E2 with a linear range between 5 pg mL–1 and 10 ng mL–1 (R2 = 0.973), and the detection capability of a definite low concentration level was 5 pg mL–1 (S/N = 3). Overall, this novel aptamer holds great promise as a valuable tool for future studies on the role of E2 in various physiological and pathological processes and for developing sensitive and specific diagnostic assays for E2 detection in clinical applications. Full article
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18 pages, 3265 KiB  
Article
Ionophore-Based Polymeric Sensors for Potentiometric Assay of the Anticancer Drug Gemcitabine in Pharmaceutical Formulation: A Comparative Study
by Gamal A. E. Mostafa, Maha F. El-Tohamy, Essam A. Ali, Rashad Al-Salahi, Mohamed W. Attwa and Haitham AlRabiah
Molecules 2023, 28(22), 7552; https://doi.org/10.3390/molecules28227552 - 12 Nov 2023
Viewed by 786
Abstract
Gemcitabine is a chemotherapeutic agent used to treat various malignancies, including breast and bladder cancer. In the current study, three innovative selective gemcitabine hydrochloride sensors are developed using 4-tert-butylcalix-[8]-arene (sensor 1), β-cyclodextrin (sensor 2), and γ-cyclodextrin (sensor 3) as ionophores. The three sensors [...] Read more.
Gemcitabine is a chemotherapeutic agent used to treat various malignancies, including breast and bladder cancer. In the current study, three innovative selective gemcitabine hydrochloride sensors are developed using 4-tert-butylcalix-[8]-arene (sensor 1), β-cyclodextrin (sensor 2), and γ-cyclodextrin (sensor 3) as ionophores. The three sensors were prepared by incorporating the ionophores with o-nitrophenyl octyl ether as plasticizer and potassium tetrakis(4-chlorophenyl) borate as ionic additive into a polyvinyl chloride polymer matrix. These sensors are considered environmentally friendly systems in the analytical research. The linear responses of gemcitabine hydrochloride were in the concentration range of 6.0 × 10−6 to 1.0 × 10−2 mol L−1 and 9.0 × 10−6 to 1.0 × 10−2 mol L−1 and 8.0 × 10−6 to 1.0 × 10−2 mol L−1 for sensors 1, 2, and 3, respectively. Over the pH range of 6–9, fast-Nernst slopes of 52 ± 0.6, 56 ± 0.3, and 55 ± 0.8 mV/decade were found in the same order with correlation regressions of 0.998, 0.999, and 0.998, respectively. The lower limits of detection for the prepared sensors were 2.5 × 10−6, 2.2 × 10−6, and 2.7 × 10−6 mol L−1. The sensors showed high selectivity and sensitivity for gemcitabine. Validation of the sensors was carried out in accordance with the requirements established by the IUPAC, while being inexpensive and easy to use in drug formulation. A statistical analysis of the methods in comparison with the official method showed that there was no significant difference in accuracy or precision between them. It was shown that the new sensors could selectively and accurately find gemcitabine hydrochloride in bulk powder, pharmaceutical formulations, and quality control tests. The ionophore-based sensor shows several advantages over conventional PVC membrane sensor sensors regrading the lower limit of detection, and higher selectivity towards the target ion. Full article
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14 pages, 1593 KiB  
Article
Fabrication and Applications of Potentiometric Membrane Sensors Based on Specific Recognition Sites for the Measurement of the Quinolone Antibacterial Drug Gemifloxacin
by Gamal A.E. Mostafa, Essam A. Ali, Rashad A. Alsalahi and Haitham Alrabiah
Molecules 2023, 28(13), 5144; https://doi.org/10.3390/molecules28135144 - 30 Jun 2023
Cited by 1 | Viewed by 745
Abstract
Supramolecular gemifloxacin (GF) sensors have been developed. Supramolecular chemistry is primarily concerned with noncovalent intermolecular and intramolecular interactions, which are far weaker than covalent connections, but they can be exploited to develop sensors with remarkable affinity for a target analyte. In order to [...] Read more.
Supramolecular gemifloxacin (GF) sensors have been developed. Supramolecular chemistry is primarily concerned with noncovalent intermolecular and intramolecular interactions, which are far weaker than covalent connections, but they can be exploited to develop sensors with remarkable affinity for a target analyte. In order to determine the dose form of the quinolone antibacterial drug gemifloxacin, the current study’s goal is to adapt three polyvinylchloride (PVC) membrane sensors into an electrochemical technique. Three new potentiometric membrane sensors with cylindric form and responsive to gemifloxacin (GF) were developed. The sensors’ setup is based on the usage of o-nitrophenyl octyl ether (o-NPOE) as a plasticizer in a PVC matrix, β-cyclodextrin (β-CD) (sensor 1), γ-cyclodextrin (γ-CD) (sensor 2), and 4-tert-butylcalix[8]arene (calixarene) (sensor 3) as an ionophore, potassium tetrakis (4-chlorophenyl) borate (KTpClPB) as an ion additive for determination of GF. The developed method was verified according to IUPAC guidelines. The sensors under examination have good selectivity for GF, according to their selectivity coefficients. The constructed sensors demonstrated a significant response towards to GF over a concentration range of 2.4 × 10−6, 2.7 × 10−6, and 2.42 × 10−6 mol L−1 for sensors 1, 2, and 3, respectively. The sensors showed near-Nernstian cationic response for GF at 55 mV, 56 mV, and 60 mV per decade for sensors 1, 2, and 3, respectively. Good recovery and relative standard deviations during the day and between days are displayed by the sensors. They demonstrated good stability, quick response times, long lives, rapid recovery, and precision while also exhibiting good selectivity for GF in various matrices. To determine GF in bulk and dose form, the developed sensors have been successfully deployed. The sensors were also employed as end-point indicators for titrating GF with sodium tetraphenyl borate. Full article
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16 pages, 9985 KiB  
Article
Screening and Identification of ssDNA Aptamers for Low-Density Lipoprotein (LDL) Receptor-Related Protein 6
by Xiaomin Zhang, Ge Yang, Wenjing Liu, Qing Liu, Zhuoran Wang, Kelong Fan, Feng Qu and Yuanyu Huang
Molecules 2023, 28(9), 3838; https://doi.org/10.3390/molecules28093838 - 30 Apr 2023
Cited by 2 | Viewed by 1747
Abstract
Low-density lipoprotein receptor-related protein 6 (LRP6), a member of the low-density lipoprotein receptor (LDLR) family, displays a unique structure and ligand-binding function. As a co-receptor of the Wnt/β-catenin signaling pathway, LRP6 is a novel therapeutic target that plays an important role in the [...] Read more.
Low-density lipoprotein receptor-related protein 6 (LRP6), a member of the low-density lipoprotein receptor (LDLR) family, displays a unique structure and ligand-binding function. As a co-receptor of the Wnt/β-catenin signaling pathway, LRP6 is a novel therapeutic target that plays an important role in the regulation of cardiovascular disease, lipid metabolism, tumorigenesis, and some classical signals. By using capillary electrophoresis–systematic evolution of ligands by exponential enrichment (CE-SELEX), with recombinant human LRP-6 as the target, four candidate aptamers with a stem-loop structure were selected from an ssDNA library—AptLRP6-A1, AptLRP6-A2, AptLRP6-A3, and AptLRP6-A4. The equilibrium dissociation constant KD values between these aptamers and the LRP6 protein were in the range of 0.105 to 1.279 μmol/L, as determined by CE-LIF analysis. Their affinities and specificities were further determined by the gold nanoparticle (AuNP) colorimetric method. Among them, AptLRP6-A3 showed the highest affinity with LRP6-overexpressed human breast cancer cells. Therefore, the LRP6 aptamer identified in this study constitutes a promising modality for the rapid diagnosis and treatment of LRP6-related diseases. Full article
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10 pages, 1013 KiB  
Article
Quantitative Detection of Natural Rubber Content in Eucommia ulmoides by Portable Pyrolysis-Membrane Inlet Mass Spectrometry
by Minmin Guo, Mingjian Zhang, Shunkai Gao, Lu Wang, Jichuan Zhang, Zejian Huang and Yiyang Dong
Molecules 2023, 28(8), 3330; https://doi.org/10.3390/molecules28083330 - 10 Apr 2023
Cited by 2 | Viewed by 1528
Abstract
Eucommia ulmoides gum (EUG) is a natural polymer predominantly consisting of trans-1,4-polyisoprene. Due to its excellent crystallization efficiency and rubber-plastic duality, EUG finds applications in various fields, including medical equipment, national defense, and civil industry. Here, we devised a portable pyrolysis-membrane inlet mass [...] Read more.
Eucommia ulmoides gum (EUG) is a natural polymer predominantly consisting of trans-1,4-polyisoprene. Due to its excellent crystallization efficiency and rubber-plastic duality, EUG finds applications in various fields, including medical equipment, national defense, and civil industry. Here, we devised a portable pyrolysis-membrane inlet mass spectrometry (PY-MIMS) approach to rapidly, accurately, and quantitatively identify rubber content in Eucommia ulmoides (EU). EUG is first introduced into the pyrolyzer and pyrolyzed into tiny molecules, which are then dissolved and diffusively transported via the polydimethylsiloxane (PDMS) membrane before entering the quadrupole mass spectrometer for quantitative analysis. The results indicate that the limit of detection (LOD) for EUG is 1.36 μg/mg, and the recovery rate ranges from 95.04% to 104.96%. Compared to the result of pyrolysis-gas chromatography (PY-GC), the average relative error is 1.153%, and the detection time was reduced to less than 5 min, demonstrating that the procedure was reliable, accurate, and efficient. The method has the potential to be employed to precisely identify the rubber content of natural rubber-producing plants such as Eucommia ulmoides, Taraxacum kok-saghyz (TKS), Guayule, and Thorn lettuce. Full article
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14 pages, 1525 KiB  
Article
Assessment of Lipophilicity Parameters of Antimicrobial and Immunosuppressive Compounds
by Dawid Wardecki, Małgorzata Dołowy and Katarzyna Bober-Majnusz
Molecules 2023, 28(6), 2820; https://doi.org/10.3390/molecules28062820 - 21 Mar 2023
Cited by 2 | Viewed by 1614
Abstract
Lipophilicity in addition to the solubility, acid-base character and stability is one of the most important physicochemical parameters of a compound required to assess the ADMET properties (absorption, distribution, metabolism, excretion and toxicity) of a bioactive molecule. Therefore, the subject of this work [...] Read more.
Lipophilicity in addition to the solubility, acid-base character and stability is one of the most important physicochemical parameters of a compound required to assess the ADMET properties (absorption, distribution, metabolism, excretion and toxicity) of a bioactive molecule. Therefore, the subject of this work was to determine the lipophilicity parameters of selected antimicrobial and immunosuppressive compounds such as delafloxacin, linezolid, sutezolid, ceftazidime, everolimus and zotarolimus using thin-layer chromatography in reversed phase system (RP-TLC). The chromatographic parameters of lipophilicity (RMW) for tested compounds were determined on different stationary phases: RP18F254, RP18WF254 and RP2F254 using ethanol, acetonitrile, and propan-2-ol as organic modifiers of mobile phases used. Chromatographically established RMW values were compared with partition coefficients obtained by different computational methods (AlogPs, AClogP, AlogP, MlogP, XlogP2, XlogP3, logPKOWWIN, ACD/logP, milogP). Both cluster and principal component analysis (CA and PCA) of the received results allowed us to compare the lipophilic nature of the studied compounds. The sum of ranking differences analysis (SRD) of all lipophilicity parameters was helpful to select the most effective method of determining the lipophilicity of the investigated compounds. The presented results demonstrate that RP-TLC method may be a good tool in determining the lipophilic properties of studied substances. Obtained lipophilic parameters of the compounds can be valuable in the design of their new derivatives as efficient antimicrobial and immunosuppressive agents. Full article
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10 pages, 2454 KiB  
Communication
A Novel Fluorescent Aptasensor for Arsenic(III) Detection Based on a Triple-Helix Molecular Switch
by Min Yuan, Ye Yang, Nguyen Thi Quynh Chau, Qinqin Zhang, Xiuxiu Wu, Jiaye Chen, Zhiwei Wu, Heng Zhong, Yuanyuan Li and Fei Xu
Molecules 2023, 28(5), 2341; https://doi.org/10.3390/molecules28052341 - 03 Mar 2023
Cited by 1 | Viewed by 1333
Abstract
A novel aptamer-based fluorescent-sensing platform with a triple-helix molecular switch (THMS) was proposed as a switch for detecting the arsenic(III) ion. The triple helix structure was prepared by binding a signal transduction probe and arsenic aptamer. Additionally, the signal transduction probe labeled with [...] Read more.
A novel aptamer-based fluorescent-sensing platform with a triple-helix molecular switch (THMS) was proposed as a switch for detecting the arsenic(III) ion. The triple helix structure was prepared by binding a signal transduction probe and arsenic aptamer. Additionally, the signal transduction probe labeled with fluorophore (FAM) and quencher (BHQ1) was employed as a signal indicator. The proposed aptasensor is rapid, simple and sensitive, with a limit of detection of 69.95 nM. The decrease in peak fluorescence intensity shows a linear dependence, with the concentration of As(III) in the range of 0.1 µM to 2.5 µM. The whole detection process takes 30 min. Moreover, the THMS-based aptasensor was also successfully used to detect As(III) in a real sample of Huangpu River water with good recoveries. The aptamer-based THMS also presents distinct advantages in stability and selectivity. The proposed strategy developed herein can be extensively applied in the field of food inspection. Full article
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11 pages, 1641 KiB  
Article
A Novel Aptamer-Imprinted Polymer-Based Electrochemical Biosensor for the Detection of Lead in Aquatic Products
by Nianxin Zhu, Xinna Liu, Kaimin Peng, Hui Cao, Min Yuan, Tai Ye, Xiuxiu Wu, Fengqin Yin, Jinsong Yu, Liling Hao and Fei Xu
Molecules 2023, 28(1), 196; https://doi.org/10.3390/molecules28010196 - 26 Dec 2022
Cited by 6 | Viewed by 1536
Abstract
Lead contamination in aquatic products is one of the main hazard factors. The aptasensor is a promising detection method for lead ion (Pb(II)) because of its selectivity, but it is easily affected by pH. The combination of ion-imprinted polymers(IIP) with aptamers may improve [...] Read more.
Lead contamination in aquatic products is one of the main hazard factors. The aptasensor is a promising detection method for lead ion (Pb(II)) because of its selectivity, but it is easily affected by pH. The combination of ion-imprinted polymers(IIP) with aptamers may improve their stability in different pH conditions. This paper developed a novel electrochemical biosensor for Pb(II) detection by using aptamer-imprinted polymer as a recognition element. The glassy carbon electrode was modified with gold nanoparticles and aptamers. After the aptamer was induced by Pb(II) to form a G-quadruplex conformation, a chitosan-graphene oxide was electrodeposited and cross-linked with glutaraldehyde to form an imprint layer, improving the stability of the biosensor. Under the optimal experimental conditions, the current signal change (∆I) showed a linear correlation of the content of Pb(II) in the range of 0.1–2.0 μg/mL with a detection limit of 0.0796 μg/mL (S/N = 3). The biosensor also exhibited high selectivity for the determination of Pb(II) in the presence of other interfering metal ion. At the same time, the stability of the imprinted layer made the sensor applicable to the detection environment with a pH of 6.4–8.0. Moreover, the sensor was successfully applied to the detection of Pb(II) in mantis shrimp. Full article
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Review

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17 pages, 1689 KiB  
Review
Molecular Biomarkers and Recent Liquid Biopsy Testing Progress: A Review of the Application of Biosensors for the Diagnosis of Gliomas
by Yuanbin Wu, Xuning Wang, Meng Zhang and Dongdong Wu
Molecules 2023, 28(15), 5660; https://doi.org/10.3390/molecules28155660 - 26 Jul 2023
Cited by 1 | Viewed by 978
Abstract
Gliomas are the most common primary central nervous system tumors, with a high mortality rate. Early and accurate diagnosis of gliomas is critical for successful treatment. Biosensors are significant in the detection of molecular biomarkers because they are simple to use, portable, and [...] Read more.
Gliomas are the most common primary central nervous system tumors, with a high mortality rate. Early and accurate diagnosis of gliomas is critical for successful treatment. Biosensors are significant in the detection of molecular biomarkers because they are simple to use, portable, and capable of real-time analysis. This review discusses several important molecular biomarkers as well as various biosensors designed for glioma diagnosis, such as electrochemical biosensors and optical biosensors. We present our perspectives on the existing challenges and hope that this review can promote the improvement of biosensors. Full article
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