Superwettable Electrochemical Biosensor toward Detection of Cancer Biomarkers.

Bioinspired superwettable micropatterns that combine two extreme states of superhydrophobicity and superhydrophilicity with the ability to enrich and absorb microdroplets are suitable for versatile and robust sensing applications. Here we introduce a superwettable microchip that integrates superhydrophobic-superhydrophilic micropatterns and a nanodendritic electrochemical biosensor toward the detection of prostate cancer biomarkers. On the superwettable microchip, the superhydrophobic area could confine the microdroplets in superhydrophilic microwells; such behavior is extremely helpful for reducing the amount of analytical solution. In contrast, superhydrophilic microwells exhibit a high adhesive force toward microdroplets, and the nanodendritic structures can improve probe-binding capacity and response signals, thus greatly enhancing the sensitivity. Sensitive and selective detection of prostate cancer biomarkers including miRNA-375, miRNA-141, and prostate-specific antigen on a single microchip is also achieved. Such a superwettable microchip with high sensitivity, low sample volume, and upside-down detection capability in a single microdroplet shows great potential to fabricate portable devices toward complex biosensing applications.