MBene as novel and effective electrochemical material used to enhance paper-based biosensor for point-of-care testing ctDNA from mice serum

Abstract

The development of sensitive point-of-care testing (POCT) circulating tumor DNA (ctDNA) is important for the non-invasive diagnosis of cancer and targeted therapy, especially in the low-resource areas. The electrochemical paper-based analytical device (ePAD) provides an ideal method that is few explored in ctDNA assay. Moreover, material with good electrochemical properties and sample pretreatment for effectively enriching target ctDNA could further improve the detection performance. Herein, we applied magnetic clutch probe to successfully pre-enrich ctDNA and established an ePAD for ctDNA detection, in which MBene/Au as sensing substrates for signal amplification and offering more probe binding sites. MBene with good electronic properties show its potential in electrode interface modification according to the DFT theory and experiments study via comparing with MXene. The introduction of MBene/Au synergistically improved the electron transfer and supplied more effective area. Two electrochemical assays strategies turn-off and turn-on were simultaneously applied to confirm the detection accuracy, and it exhibited a detection linear range in 1–50 pM and a limit in 178 fM and 216 fM respectively after 30 min incubation with extracted ctDNA. Moreover, the biosensor was studied in selectivity, reproducibility and stability with favorable results. In evaluation of detecting reliability, the assay results for ctDNA from tumor cell sample and mice serum were compared with conventional qPCR method and obtained high correlation (R2 = 0.993 and 0.995). Hence, this work broadens a new application of MBene into electrochemical sensing and provides a promising POCT platform for ctDNA or other analytes.