Aptamer probe indirect functionalization enables the reusable detection of cancer protein biomarkers in graphene field-effect transistor

Recently, aptameric graphene field-effect transistors (GFET) have emerged in the field of in situ detection of cancer protein biomarkers, thanks to their advantages of fast response, high specificity, and high sensitivity. However, factors such as non-usable have limited their productization process. Here, we propose a novel aptamer indirect functionalization method that enables the reconfigurable modification for aptamer probes on graphene surface, thereby achieving reusable aptameric-GFET detection for protein biomarkers with the calibrated signals. Furthermore, a novel crosslinker, tetrakis(4-carboxyphenyl)pophyrin (TCPP), is exploited for the signal amplification. Results show that our proposed reusable sensor can respond to carcinoembryonic antigen (CEA), a representative cancer protein biomarker, concentration change in 6–8 min with an estimated limit of detection (LOD) of 1.09 ng/mL in 1× phosphate buffered saline (PBS), and the signal is increased by more than half compared to the conventional method. Dissociation occurs at the target temperature and signal degradation is less than 5% after 3 cycles and 20% after 14 days of storage and 10 cycles. Our work provides a novel strategy for measuring CEA quantitatively and sensitively with rapid response, which holds great potential for a wide range of medical application and leads to powerful biomarkers detection devices in healthcare.