Non-Fouling TiO₂ Nanomaterial-Based Biosensors for Clinical Biomarker Detection

Non-fouling refers to the prevention of undesirable biological or chemical reactions on sensing surfaces, which enhances the performance of sensing systems. Biofouling poses a significant challenge in achieving specific interactions in biosensors, particularly in the context of serological biomarker analysis. When analyzing clinical samples, implementing anti-biofouling measures is crucial. However, the criteria for selecting appropriate anti-biofouling options remain inadequately defined. To overcome these issues, the significance of blocking agents on bioreceptor-modified surfaces to enhance specificity is emphasized. Besides, titanium dioxide (TiO₂) nanomaterial-hybrid biosensors have been desired for analyzing human serological biomarkers, as TiO₂ enhances the non-fouling nature of sensing surfaces. TiO₂ is a semiconductor material used in biosensing applications due to its high surface area, excellent chemical stability, and biocompatibility. To utilize TiO₂ in a non-fouling environment, surface modifications have been implemented to reduce the undesirable adhesion of biological molecules. Biosensors based on TiO₂ nanomaterials have exhibited remarkable sensitivity and specificity, along with rapid detection capabilities. These TiO₂ biosensors can analyze human serum in as little as 2 s, achieving average sample concentrations in the nanomolar range and a correlation coefficient of 0.99. This overview provides an update on TiO₂ electrical biosensors for detecting serological markers and demonstrating excellent performance in clinical diagnosis. Besides, discusses unresolved issues, including the limitations of electrical biosensors in real-time point-of-care applications and the importance of Internet of Things.