Cryptosporidium ( Crypto ) is a microscopic parasite that leads to diarrhea and gastroenteritis in humans. The oocysts of Crypto present a significant risk to water supplies because they are highly resistant to common disinfectants. To prevent potential outbreaks, it is essential to monitor and detect this pathogen at trace levels. In this work, a manganese‐carbon quantum dot titanium ternary composite (CQD‐TiO 2 –MnO 2 ) is proposed as a material for immobilizing the aptamer on the electrode surface. Various techniques, including X‐ray spectroscopy, high‐resolution transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy, were employed to confirm the synthesis of the materials. The techniques revealed a uniform distribution of nanomaterials, and the ternary composite contains oxygen‐containing groups that facilitate electron movement and ensure the stable attachment of the aptamer. The electrochemical tests demonstrated that the GCE‐CQD‐TiO 2 –MnO 2 ‐Apt 1 ‐BSA electrode exhibited enhanced electrochemical kinetics and conductivity. The study achieved a low detection limit of 0.0012 ng mL −1, a limit of quantification of 0.005 ng mL −1 , a linear range of 0.0055–0.0070 ng mL −1 , and a sensitivity of 0.197 mA µM −1 . The developed aptasensor showed excellent performance in both dam and river water, with recoveries ranging from 75% to 96%.
Nompetsheni et al. (Thu,) studied this question.