An antifouling and antibacterial electrochemical biosensor for detecting aminopeptidase N cancer biomarker in human urine

Abstract

The sensitivity and accuracy of a biosensor for detecting biomarkers in body fluids will be disturbed not only by the non-specific adsorption of molecules in the biofluids but also by bacteria from the external environment, and it is therefore urgently needed to develop biosensors integrated with antifouling and antibacterial abilities. Herein, a dual-function sensing interface that possessed both antifouling and antibacterial properties was constructed based on the incorporation of antimicrobial peptide (AMP) into the amyloid-like BSA (ALBSA) with antifouling property. The composite biomaterial of ALBSA-AMP was then connected to polyaniline (PANI) modified electrode, followed by immobilization of the peptide aptamer specific for the aminopeptidase N (APN) to fabricate an antifouling electrochemical biosensor with antibacterial capability. The biosensor exhibited superior antifouling and antibacterial abilities with incubation time of 90 min for APN, wide linear range of 100.0 pg mL−1 to 10.0 μg mL−1 and low limit of detection of 24.25 pg mL−1. The accuracy of the biosensor for APN detection in real human urine was comparable to that of the commercial ELISA kits, which was attributed to the excellent selectivity and high sensitivity of the biosensor. This strategy holds particular promise for the fabrication of biosensors to be used for biomarker detection in human fluids with the presence of bacteria.