The exploration of graphitic carbon nitride (g-C3N4), a two-dimensional (2D) metal-free polymer semiconducting material, is largely discussed due to its large specific surface area, high electrical conductivity, thermal stability, and adaptable electronic structure. The adaption of sulfur (S) and phosphorous (P) atoms into the layers of g-C3N4 increases the electrochemical performance of detecting nilutamide (NT). The aggregation severity can be decreased by integrating S/P into g-C3N4, thereby improving surface area and electrical conductance. The g-C3N4, S/gC3N4, P/g-C3N4, and S/P/g-C3N4 were studied with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Ultraviolet visible spectroscopy (UV), Thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET). The well-assigned S/P/g-C3N4 exhibited a good crystalline structure with more active sites for improved electron transfer toward NT detection. Both differential pulse voltammetry (DPV) and amperometry (IT) was studied for NT detection. The electrochemical studies were done with a linear range of 0.019–1.17 μM to 5.36–1891.98 μM in DPV and 0.01 μM–158.3 μM in IT technique. The attained limit of detection in DPV analysis was 3.2 nM and with IT analysis 2.4 nM. The nanocomposite S/P/g-C3N4 shows good selectivity towards NT. The fabricated electrode showed excellent repeatability, reproducibility, and stability, with a significant recovery range in real sample analysis. Display omitted •The two-dimensional metal free polymeric material graphitic carbon nitride (g-C3N4) was employed. in the present study.•To booster the performance of g-C3N4 sulfur (S) and phosphorous (P) were substituted into g-C3N4 carbon structure.•S/P/g-C3N4 with more active sites showed superior electrochemical performance towards nilutamide (NT) detection.•The fabricated electrode revealed good repeatability, reproducibility, stability for NT reduction analysis.•The composite material is more appropriate and enriched with more significant features opting good performances.