Flower-like copper nanocomposite-based electrochemical sensor for highly selective detection of histidine

Flower-like copper nanocomposites (Cu NFs) were synthesized through the coordination-driven assembly of Cu 2+ with protoporphyrin IX (Pp IX) for electrochemically sensing histidine (His) in blood. More interestingly, the Cu NFs-modified electrode could exhibit characteristic electrochemical peaks of CuCl at a lower and more favorable potential, which is practically advantageous. Especially, the CuCl signals would undergo a selective enhancement in the presence of His because of the specific coordination between copper ions and the imidazole moiety in His. This mechanism forms the basis of a proposed electrochemical strategy for highly selective His detection, exhibiting a linear range of 0.05 μM–100 μM. The limit of detection (LOD) for this method was calculated to be about 0.014 μM. Furthermore, the newly developed electrochemical strategy was applied to detect His in blood samples, showing analytical performances comparatively superior to those of the documented methods. This low-potential electrochemical detection strategy with enhanced signal output shows significant potential for use in the disease diagnostics and food safety analysis fields.