Sensitive and selective electrochemical biosensor based on Manganese(II) complex for simultaneous determination of adenine and guanine from clinical samples and DNA extract samples

The purines guanine and adenine are essential building blocks for nucleic acids and influence numerous biochemical processes in organisms. Elevated levels of these compounds in the bloodstream can indicate conditions such as cancer and provide insights into cellular energy status, tissue degradation, and enzyme malfunctions in metabolic pathways. This study focuses on developing a voltammetric sensor through the electropolymerization of a tetraresorcinatemanganate (II) complex on a glassy carbon electrode (poly(Mn(HR) 4 )/GCE), which was thoroughly characterized. The poly(Mn(HR) 4 )/GCE exhibited distinct, well-defined irreversible oxidative peaks for adenine and guanine. The peak currents displayed strong linearity with analyte concentrations within the 0.01–300 μM range, boasting a detection limit of 66.54 and 9.1 nm and a limit of quantifications of 221.80 and 30.23 nm, respectively. The sensor was successfully employed to detect adenine and guanine in urine, clinical blood serum, and DNA extract samples, with spike recovery rates in these samples reaching the range of 96–104 %. The interference recovery results showcased an error rate of less than 6 %, highlighting the method's superior lower detection limit and broader dynamic range compared to existing techniques. These findings underscore the potential practicality of the proposed approach for accurately determining adenine and guanine in diverse real samples with intricate matrices. • Novel poly(Mn(HR)4)/GCE was potentiodynamically fabricated to determine adenine and guanine simultaneously. • The modification of the sensor resulted in an improvement of the current intensity about 3.4 times for A and 2.4 times for G. • Adenine and guanine simultaneously oxidize electrochemically on poly(Mn(HR) 4 )/GCE under full diffusion control. • The sensor demonstrated the best response with an LOD of 66.54 nM for A and 9.10 nM for G, and an RSD of less than 2.4 %. • The ability of the developed sensor to simultaneously analyze adenine and guanine in pharmaceutical samples was confirmed.