Aptamer‐functionalized Ti₃C₂‐MXene Nanosheets with One‐step Potentiometric Detection of Programmed Death‐ligand 1

Abstract

This communication describes a simple sensitive one-step potentiometric aptasensing method for quantitative detection of a referenced therapeutic biomarker (programmed death-ligand 1, PDÀ L1). The aptasensor is constructed by modifying PDÀ L1-specific aptamer on Ti 3 C 2 -MXene nanosheets-functionalized electrode. Introduction of PDÀ L1 induces the specific reaction between PDÀ L1 and aptamer, thereby resulting in the change of spatial structures. The surface electric potential of modified electrode is shifted upon addition of PDÀ L1 proteins before and after the reaction of aptamer with the analyte. Interestingly, potentiometric aptamer with Ti 3 C 2 -MXene nanosheets can achieve a higher sensitivity and a lower detection limit toward target PDÀ L1 relative to aptamer-modified electrode. Experimental results indicated that the linear range and detection limit of using Ti 3 C 2 -MXene nanosheets were 0.01-100 ng mL À 1 and 7.8 pg mL À 1 PDÀ L1, respectively. Meanwhile, the specificity, reproducibility, storing stability and accuracy of potentiometric aptasensor are acceptable for the screening of PDÀ L1 in human serum samples.