A flexible capacity-metric creatinine sensor based on polygon-shape polyvinylpyrrolidone/CuO and Fe2O3 NRDs electrodeposited on three-dimensional TiO2-V2O5-Polypyrrole nanocomposite

Selective Single-Bacterium Analysis and Motion Tracking Based on Conductive Bulk-Surface Imprinting

Conductive molecular imprinting (MI) shows great potential in enhancing the selectivity of electrochemical bacterial assays, but its efficiency is hindered due to the rigid long-conjugated structure and imprecise specific recognition sites. It is thus urgent to activate the surface MI with clear specific recognition sites toward the bacteria and to develop a single-bacterium monitoring technique for precisely verifying the MI efficiency microscopically. Herein, using lipopolysaccharides and Escherichia coli (E. coli) cells as the surface and bulk templates, respectively, an ideal monomer is successfully predicted by the density functional theory, and the MI with clear and high-precision recognition sites for bacterial matching is prepared. A deep learning-assisted single-bacteria movement trajectory tracking method is developed, and the trained model can effectively recognize and track the movement paths and velocities of both single and group bacteria. Accordingly, the surface MI capture process of the specific recognition sites for E. coli is systematically monitored and analyzed, opening the way for establishing a multidimensional system for characterizing the selective capture process of single and group bacteria by MI polymers. Moreover, the as-prepared electrochemical sensors accomplish the rapid, sensitive sensing of E. coli with a detection limit of 10 CFU/mL and a 433%-increased selectivity, which could promote the development of finer-grained bacterial imprinting techniques and smart bacterial biosensors.

Advances in the Use of Conducting Polymers for Healthcare Monitoring

Conducting polymers (CPs) are an innovative class of materials recognized for their high flexibility and biocompatibility, making them an ideal choice for health monitoring applications that require flexibility. They are active in their design. Advances in fabrication technology allow the incorporation of CPs at various levels, by combining diverse CPs monomers with metal particles, 2D materials, carbon nanomaterials, and copolymers through the process of polymerization and mixing. This method produces materials with unique physicochemical properties and is highly customizable. In particular, the development of CPs with expanded surface area and high conductivity has significantly improved the performance of the sensors, providing high sensitivity and flexibility and expanding the range of available options. However, due to the morphological diversity of new materials and thus the variety of characteristics that can be synthesized by combining CPs and other types of functionalities, choosing the right combination for a sensor application is difficult but becomes important. This review focuses on classifying the role of CP and highlights recent advances in sensor design, especially in the field of healthcare monitoring. It also synthesizes the sensing mechanisms and evaluates the performance of CPs on electrochemical surfaces and in the sensor design. Furthermore, the applications that can be revolutionized by CPs will be discussed in detail.