Temperature Abetted Synthesis of Zeolitic Imidazolate Framework-Derived 3D Zn@N–C with MXene and Gold Nanostars-Based Immunosensor for the Detection of Prostate-Specific Antigen

Prostate cancer (PC) is a malignant tumor that develops in the prostate cells of males and is the second most common cancer in men. Therefore, an early and accurate diagnosis of PC is crucial. Current diagnostic approaches are insufficient, highlighting an urgent need for alternative analytical platforms that target specific PC biomarkers in body fluids. With this instigation, we designed an environmentally friendly, disposable, and label-free electrochemical immunosensor based on gold nanostars decorated on ZIF-8-derived zinc with nitrogen-doped carbon at different temperatures (600-1000 °C) with a titanium carbide (MXene) nanosheet (AuNSs/Zn@N-C/MXene) composite modified with a screen-printed carbon electrode (SPCE) to detect prostate-specific antigen (PSA). Zn@N-C-800 °C with MXene possesses high conductivity and catalytic activity, a large surface area, and abundant active sites for PSA immunosensors. The AuNSs further enhanced the conductivity of Zn@N-C/MXene/SPCE. Cysteamine (Cys) and glutaraldehyde (Glut) were connected to the antibody (Ab) PSA to form an Ab/Glut/Cys/AuNSs/Zn@N-C-800 °C/MXene/SPCE immunosensor, which showed a direct relationship between the PSA concentration and the current response of the immunosensor. It has a linear range of 0.1 pg/mL to 1 μg/mL, with an R² = 0.993 (n = 5; RSD <2%), and a detection limit (LOD) of 8.48 fg/mL. The resultant immunosensor was highly selective, stable, and reproducible, making it a promising tool for the early diagnosis and treatment of PC.