Rational design of hydrogel/CuPc dual-improved microelectrode for sensitive detection of bisphenol A in blood.

BACKGROUND

As plastic consumption increases annually, a concerning volume of plastic waste gathers in the environment. The lengthy process of breaking down these large plastic pieces into microscopic particles is accompanied by a steady leakage of chemicals added during production into the environment, which then enters the human body through the ecosystem. However, developing portable, reliable, and fouling-resistant electrochemical sensors to detect trace levels of plasticizers (endocrine disruptors) in the human body remains a significant analytical challenge.

RESULTS

This study introduces a dual-modified electrochemical platform using a carbon fiber microelectrode (CFME) coated with gold nanostructures and agar hydrogel infused with copper phthalocyanine (CuPc). This rational regulation of multicomponents at tiny interfaces is attributed to the synergistic interactions between the excellent electrical conductivity of gold nanolayers, the hydrophilicity, biocompatibility, and antifouling properties of hydrogels, and the homogeneous distribution of electrocatalytically active sites of CuPc. Bisphenol A (BPA), a typical representative of plasticizers, was used as a model to evaluate the performance of the designed functional microelectrodes. The results show that the plentiful Cu-N4 catalytic sites in CuPc provide exceptional electrocatalytic efficiency for BPA, with the reaction being diffusion-controlled. Additionally, the response demonstrates good linearity and reproducibility across a broad concentration range. Under optimal conditions, the sensor maintained high selectivity for BPA in the presence of potential interferents in blood samples and achieved a remarkable detection limit of 420 nM.

SIGNIFICANCE: This work introduces a microelectrode functionalization method that thoughtfully regulates multiple components at microinterfaces to create synergistic effects. It offers a versatile and adaptable sensing strategy, making it easier to detect trace plasticizers with high sensitivity and selectivity. This method unlocks exciting opportunities for real-time environmental and biomedical monitoring, paving the way for truly impactful applications.