Sensitive electrochemical sensing platform based on Au nanoflower-integrated carbon fiber for detecting interleukin-6 in human serum.

Prostate cancer (PCa) is the most prevalent cancer worldwide, with a high mortality rate. The early and accurate detection of PCa is critical in reducing mortality and saving lives. Timely diagnosis can improve the chances of successful treatment using advanced technologies. In recent years, nanomaterial-based electrochemical sensing strategies have been adopted in clinical diagnosis, as they allow sensitive early-biomarker detections to be converged with a cost-effective electronic readout system. Herein, we present a flexible electrochemical immunosensor platform for detecting interleukin-6 (IL-6) based on an Au-integrated flexible carbon fiber (Au/CF) electrode prepared via electrodeposition and chemically modified to capture IL-6 antibodies. Several techniques are used to analyze the prepared Au/CF composite electrodes to confirm their morphology, structure, and elemental composition. Under optimum conditions, the fabricated immunosensor exhibits a wide linear dynamic ranging from 1 fg/mL to 1 µg/mL and a low detection limit of 0.056 fg/mL, with a sensitivity of 62.17 µA/(fg mL-1). The proposed fiber-based immunosensor is used to quantify the concentration of IL-6 in serum samples from clinical PCa patients (T3b and T4 stages), and the results are validated using the commercial Meso Scale Diagnostics (MSD) V-Plex method. The acceptable results yielded by the proposed immunosensor indicate that it can serve as a new platform to realize highly sensitive and cost-effective diagnostic strategies for the early diagnosis of PCa.

Recent Developments in Electrochemical Sensors for the Detection of Antibiotic-Resistant Bacteria.

The development of efficient point-of-care (POC) diagnostic tools for detecting infectious diseases caused by destructive pathogens plays an important role in clinical and environmental monitoring. Nevertheless, evolving complex and inconsistent antibiotic-resistant species mire their drug efficacy. In this regard, substantial effort has been expended to develop electrochemical sensors, which have gained significant interest for advancing POC testing with rapid and accurate detection of resistant bacteria at a low cost compared to conventional phenotype methods. This review concentrates on the recent developments in electrochemical sensing techniques that have been applied to assess the diverse latent antibiotic resistances of pathogenic bacteria. It deliberates the prominence of biorecognition probes and tailor-made nanomaterials used in electrochemical antibiotic susceptibility testing (AST). In addition, the bimodal functional efficacy of nanomaterials that can serve as potential transducer electrodes and the antimicrobial agent was investigated to meet the current requirements in designing sensor module development. In the final section, we discuss the challenges with contemporary AST sensor techniques and extend the key ideas to meet the demands of the next POC electrochemical sensors and antibiotic design modules in the healthcare sector.

Gold nanocubes embedded biocompatible hybrid hydrogels for electrochemical detection of H2O2.

Smart electrochemical biosensors have emerged as a promising alternative analytical diagnostic tool in recent clinical practice. However, improvement in the biocompatibility and electrical conductivity of the biosensor matrix and the immobilization of various bioactive molecules such as enzymes still remain challenging. The present research reports the synthesis of a biocompatible hydrogel network and its integration with gold nanocubes (AuNCs) for developing a novel biosensor with improved functionality. The interpenetrating hydrogel network consist of biopolymers developed using graft co-polymerization of ß-cyclodextrin (ß-CD) and chitosan (CS). The novelty of this work is in integrating the CS-g-ß-CD hydrogel network with conductive AuNCs for improving hydrogel conductivity, biosensor sensitivity and use of the material for a biocompatible sensor. The present protocol advances the state of the art for the utilization of biopolymeric hydrogels system in synergy with an enzymatic biosensing protocol for exclusively detecting hydrogen peroxide (H2O2). Immobilization of the mitochondrial protein, cytochrome c (cyt c) into the hydrogel nanocomposite matrix was performed via thiol cross-linking. This organic-inorganic hybrid nanocomposite hydrogel matrix exhibited high biocompatibility (RAW 264.7 and N2a cell lines), improved electrical conductivity to attain high sensitivity (1.2 mA mM-1 cm-2) and a low detection limit (15 × 10-9 M) for H2O2.