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Electrochemical biosensors have been applied in a broad range of clinical applications for pathogen biomarker detection and medical applications and diagnosis due to the sensitivity of electrochemical methods and the bioselectivity of the components. The complexity of clinical conditions with various biofoulants (proteins, cells, polysaccharides and lipids) severely influences the reliability and stability of sensors for direct detection or immersion under changing conditions. Therefore, designing an antifouling sensing platform that can effectively reduce undesired binding to maintain biosensor performance in optimized analysis is necessary. For this purpose, the fundamental mechanisms of fouling materials and commonly used biocompatible antifouling components have been discussed, and the relevant effective modification strategies are introduced in this review. Recent advances in these strategies are demonstrated in examples with analysis of essential modification methods for reliable sensing in non-specific binding solutions or complex biofluids. The challenges and future perspectives of modification strategies for current clinical application are also discussed in this review.

Extreme point-of-care testing (POCT) is a medical test performed at or near patients at a resource-limited condition. POCT technology has advantages over traditional medical lab tests for molecular detection and infection diagnosis, such as being simple, portable, low-cost, and user-friendly. However, some POCT devices might rely on bulky equipment, and some might be easily influenced by components in biofluid, which might result in higher prices and lower accuracy. In this paper, we demonstrated a low-cost method for detecting bacterial infection in the early stage. We designed a hand-powered centrifugal microfluidic (CMF) disc with magnetic chitosan beads (MCBs) to detect specific circulating antibodies in human whole blood. Nine identical units was used for calibration curve plotting and sample testing. The MCBs, generated with another microfluidic chip and coated with MBL proteins (biomarker of drug-resistant Streptococcus pneumoniae, DRSP, taken as an example for bacterial infection), were served as the substrate of sandwich-structured enzyme-linked immunosorbent assays (ELISA) and as the micro stirring sphere at the same time. The limit of detection (LOD) in PBS and human whole blood were 22.67 ng/mL and 24.83 ng/mL, respectively. The comparison between calibration curves from the antibody spiked in human whole blood and that in PBS was shown to prove the high compatibility and low interference of biofluid, and the recovery rate was 92 %. In conclusion, since our low-cost, time-saving, and user-friendly hand-powered CMF device with minimally consumed electricity detected the target antibody precisely, we believe that other similar assays would be feasible as well. Therefore, we are firmly convinced that this alternative POCT device may lead to the development of next-generation healthcare diagnoses.

Boronic acids (BAs) provide strong potential in orientation immobilization of antibody and the modification method is crucial for efficiency optimization. A highly effective method has been developed for rapid antibody immobilization on gold electrodes through the electrodeposition of a BA–containing linker in this study. Aniline-based BA forms a condense layer while antibody could automatically immobilize on the surface of the electrode. Compare to traditional self-assembled monolayer method, the electrodeposition process dramatically reduces the modification time from days to seconds. It also enhances the immobilized efficiency from 95 to 408 (ng/cm2) with a strong preference being exhibited for shorter aniline-based linkers.