Construction of a purine base electrochemical sensing platform based on NH2-MXene@COFTA-DH/GCE for simultaneous detection of guanine and adenine

Alterations in guanine (GA) and adenine (AE) levels within the human body are intricately linked to overall health and daily physiological functions. Therefore, it is crucial to develop an accurate and sensitive sensor for quantifying the levels of GA and AE. In this present paper, a novel electrochemical sensor NH 2 -MXene@COF TA-DH /GCE was constructed by in-situ growing COF TA-DH with high crystallinity, good thermal stability and N-rich active centers based on Schiff base condensation reaction of 1, 3, 5-tris-(4-aminophenyl) triazine (TAPT) and 2,5-dihydroxyl-terephthalaldehyde (DHTA) on highly conductive NH 2 -MXene and then modifying it on the surface of the glass carbon electrode (GCE). The highly dispersed sandwich structure of NH 2 -MXene@COF TA-DH significantly increases the specific surface area and exposes a greater number of active sites. Benefitted from remarkable synergistic effect, the sensor exhibited excellent electrochemical catalytic activity and high sensitivity for GA and AE detection. The sensing platform was successfully used for simultaneous detection of GA and AE with wide linear ranges of 0.6–230 μM and 1–450 μM and low detection limits of 0.07 μM and 0.44 μM, respectively. This study expands applications of COFs and MXene in electrochemical biosensing platform and provides a general and valuable strategy for COFs-based electrochemical sensor construction for biomedical investigations