How does the MWCNTs-BP nanocomposite enhance the performance of the electrochemical biosensor for detecting trichloroacetic acid (TCA) and sodium nitrite (NaNO2)?

The study investigates the development of an electrochemical biosensor using a nanocomposite of multi-walled carbon nanotubes (MWCNTs) and black phosphorene (BP) to detect trichloroacetic acid (TCA) and sodium nitrite (NaNO2). TCA is a corrosive liquid used in skin treatments and industrial processes, while NaNO2 is a food preservative that can pose health risks at high doses. Detecting these substances is crucial for environmental and food safety applications.

The MWCNTs-BP nanocomposite enhances the performance of the electrochemical biosensor by improving electron transfer and interfacial conductivity. The synergistic effects of BP and MWCNTs significantly increase the specific surface area and charge transfer efficiency, allowing efficient direct communication between horseradish peroxidase (HRP) and the electrode. This results in excellent sensitivity for TCA and NaNO2 detection, with linear ranges of 3.0–558.0 mmol/L (LOD as 1.0 mmol/L) for TCA and 0.1–13.6 mmol/L (LOD as 0.03 mmol/L) for NaNO2. The biosensor also demonstrates strong practical applicability in detecting TCA and NaNO2 in real samples like medical facial peel solutions and pickled vegetable soaking water.