Electrode fouling is a phenomenon that can severely affect the analytical characteristics of a technique or a sensor, such as sensitivity, detection limit, reproducibility, and overall reliability. Electrode fouling generally involves the passivation of an electrode surface by a fouling agent that forms an increasingly impermeable layer on the electrode, inhibiting the direct contact of an analyte of interest with the electrode surface for electron transfer. Some potential fouling agents include proteins, phenols, amino acids, neurotransmitters, and other biological molecules. Various antifouling strategies have been reported to reduce or eliminate electrode fouling. Most antifouling strategies exploit a protective layer or barrier on an electrode substrate to prevent the fouling agent from reaching the electrode surface. Although such strategies can be quite effective, they are inappropriate for systems in which the analyte itself is also the fouling agent. In such cases, other strategies must be used, including electrode surface modification and electrochemical activation. In this review, recent strategies to minimise and efforts to overcome electrode fouling across a diverse range of analytes and fouling agents will be presented.
This paper reviews hyphenated differential mobility spectrometry (DMS) technology. DMS is a type of ion mobility spectrometry (IMS) also called high-field asymmetric waveform IMS. It is widely used in the detection of chemical warfare agents, explosives, drugs, and volatile organic compounds. Stand-alone DMS analysis of complex mixtures in real-field applications is challenging. Hyphenated DMS can improve resolution for rapid separation and detection. This review focuses on hyphenated DMS, including gas chromatography-DMS, DMS-mass spectrometry (MS), DMS-IMS, IMS-DMS, and DMS-DMS, as well as their associated principles, applications, and research procedures. Key problems in hyphenated DMS are considered.
