Reproducible peptide oxidation was observed using a homebuilt liquid microjunction-surface sampling probe (LMJ-SSP) platform for analyzing peptide standards. Although electrochemical oxidation and corona discharges have previously been associated with analyte oxidation in electrospray ionization (ESI) and ESI-related ambient ionization mass spectrometry (MS) methods, they were unlikely the causes for the peptide oxidation observed in the LMJ-SSP studies. A systematic investigation demonstrated that analyte oxidation was induced during the droplet drying on a solid surface through liquid-solid electrification processes. To minimize unwanted analyte oxidation, the water content in the sample solution should be decreased and the use of hydroxyl-functionalized substrates, such as glass slides, should be avoided. In addition, if water is an essential solvent component, adding an antioxidant, such as ascorbic acid, to the sample solution before droplet evaporation on the solid surface could lower the percentage of analyte oxidation. The present findings apply to all the MS methods that involve drying microliters of sample solution onto a suitable substrate in their sample preparation protocols.
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http://dx.doi.org/10.1021/acs.analchem.3c01411 | DOI Listing |
Mikrochim Acta
January 2025
Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand.
Carcinoembryonic antigen (CEA) and C-reactive protein (CRP) are biomacromolecules known as cancer and inflammatory markers. Thus, they play a crucial role in early cancer diagnosis, post-treatment recurrence detection, and tumor risk assessment. This paper describes the development of an ultrasensitive and selective imprinted paper-based analytical device (PAD) as impedance sensor for determination of CEA and CRP in serum samples for point-of-care testing (POCT).
View Article and Find Full Text PDFAnal Chim Acta
March 2025
Zhejiang Key Laboratory of Advanced Optical Functional Materials and Devices, Ningbo University, Ningbo, 315211, China; Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province, Ningbo University, Ningbo, 315211, China. Electronic address:
Background: Permethrin is a pesticide used to kill insects, and once used in excess, it poses a great threat to the environment and human health, therefore, it is necessary to realize the rapid and accurate detection of permethrin. Fiber optic surface enhanced Raman scattering (SERS) probes have the advantages of small volume and can be used for remote monitoring, which have great potential for application in achieving in-situ detection of pesticide residues.
Results: Fiber taper waist (FTW) SERS probes modified by silver nanocubes-graphene oxide (Ag NCs-GO) composite structures were prepared for in situ detection of permethrin in lake water.
J Pharm Biomed Anal
January 2025
Institute of Inorganic and Analytical Chemistry, University of Münster, Corrensstraße 48, Münster 48149, Germany. Electronic address:
Minocycline is an antibiotic of the tetracycline family which is widely used to treat a range of medical conditions. Although it has been in use for more than 50 years, little information is available on its metabolism in the human body. In this study, we simulate the biotransformation of minocycline by means of electrochemistry coupled to mass spectrometry.
View Article and Find Full Text PDFTalanta
January 2025
Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg D. Obradovića 3, 21000, Novi Sad, Serbia.
The sustainable material, biochar (BC) from a hardwood source, was synthesized via pyrolysis process at 400 °C (BC400) and 700 °C (BC700) and used as a modifier during the electrochemical sensor design. The prepared BCs were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and elemental analysis (CHNS). The development of rapid analytical techniques for detecting pesticides employing a low-cost carbon paste electrode (CPE) modified with BC is a novel strategy to provide a sensitive response to water pollution.
View Article and Find Full Text PDFTalanta
January 2025
Department of Laboratory Medicine, Taihe hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, China; Hubei Key Laboratory of Embryonic Stem Cell research, Hubei University of Medicine, Shiyan, 442000, Hubei, China; Clinical molecular diagnostic center, Taihe hospital, Hubei University of Medicine, Shiyan, Hubei, 442000, China. Electronic address:
Endothelial-to-mesenchymal transition (EndMT) plays a crucial role in the initiation and progression of atherosclerosis and various disease processes. Cluster of differentiation 31 (CD31) is a significant marker in EndMT. Detecting CD31 is essential for early-stage monitoring of EndMT and diagnosing atherosclerosis.
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