Organic-free NiSe2, CoSe2, and NiSe2/CoSe2 for non-enzymatic glucose sensing

Abstract

The development of low-cost, stable, and highly efficient electrocatalysts is essential for replacing noble metal-based catalysts in sensor applications. The effectiveness of an electrocatalyst depends significantly on the free movement of electrons across the nanocatalyst’s surface. However, the organic surfactant molecules commonly used to stabilize nanoparticles tend to act as insulators, which can hinder electron conductivity. Thus, creating nanocatalysts with unobstructed surfaces that promote electron movement is crucial. This study describes the synthesis of organic surfactant-free NiSe₂ (sf-NiSe₂), CoSe₂ (sf-CoSe₂), and a composite of NiSe₂/CoSe₂ (sf-NiSe₂/CoSe₂) and investigates their electrocatalytic oxidation capabilities for non-enzymatic glucose sensing. We explored their comparative effectiveness as non-enzymatic glucose sensors and confirmed their excellent physicochemical stability. The results demonstrated the efficacy and sensing capabilities of the synthesized materials for the electrochemical detection of glucose. Notably, the composite sf-NiSe₂/CoSe₂ exhibited a superior electrochemical response, long-term stability, and robust anti-interference ability compared to the individual materials. This composite achieved a limit of detection of 0.0588 mM, a sensitivity of 0.0896 mA mM⁻¹ cm⁻², and a rapid response time of 0.603 s. These findings highlight the considerable potential of sf-NiSe₂/CoSe₂ as a non-enzymatic glucose sensor material. This research could pave the way for a new, affordable, reliable electrochemical glucose sensor platform.