Comparative analysis of electrochemical and spectroscopic sensing of enzymatic reactions: Lactate dehydrogenase-A case study

In this work, electrochemical methods are evaluated as a promising alternative to UV–vis spectroscopy for monitoring Lactate Dehydrogenase (LDH) activity through amperometric detection of NADH, with the aim of screening and assessing the efficacy of potential anticancer drugs. A Ti-modified glassy carbon electrode is used as working electrode, demonstrating effective performance in quantifying NADH. The chronoamperometric measurements conducted at 0.66 V yield a linear response over increasing NADH concentrations. The sensitivity is 0.614 μA cm −2 mM −1 , with a limit of detection (LOD) of 27.58 μM and a limit of quantification (LOQ) of 91.92 μM. The proposed electrochemical set-up shows good selectivity, with no interference-induced signals while maintaining a stable amperometric response upon variations in NADH concentrations. Although the LOD may benefit from further optimization, this electrochemical approach offers some advantages compared to optical methods because it provides higher sensitivity and stability from interference caused by several compounds. • Electrochemical quantification of NADH is more selective than UV–vis spectroscopy. • Three-electrode set-up successfully monitors lactate dehydrogenase reaction. • The effect of potential inhibitors test on the activity of lactate dehydrogenase. • Lactate dehydrogenase was covalently immobilized on functionalized mesoporous silica. • Simple preparation of Titanium modified glassy carbon electrode.