This paper presents an electrochemical immunosensor using a graphene/multi-walled carbon nanotube (MWCNT) composite platform for detecting the cardiovascular marker C-reactive protein (CRP). The immunosensor exhibited a linear detection range of 0.20–100 ng/mL CRP with a low limit of detection reaching 0.081 ng/mL. The composite material provided a 3D porous structure that allowed efficient antibody immobilization and minimized steric hindrance. The sensor showed high specificity, with minimal response to interfering substances. Using differential pulse voltammetry, the immunosensor demonstrated exceptional precision, rapid detection, and a direct correlation between CRP concentration and sensor response current. Overall, this work highlights the potential of the graphene/MWCNT composite platform as a robust tool for early CRP detection and cardiovascular disease risk assessment. The immunosensor provides sensitive and selective CRP quantification that could enable timely clinical intervention for at-risk individuals.

Nitrogen (N)-doped protein-based carbon as platinum (Pt) catalyst supports from tofu for oxygen reduction reactions are synthesized using a carbonization and reduction method. We successfully prepare 5 wt% Pt@N-doped protein-based carbon, 10 wt% Pt@N-doped protein-based carbon, and 20 wt% Pt@N-doped protein-based carbon. The morphology and structure of the samples are characterized by field emission scanning electron microscopy and transmission electron micro scopy, and crystllinities and chemical bonding are identified using X-ray diffraction and X-ray photoelectron spectroscopy. The oxygen reduction reaction are measured using a linear sweep voltammogram and cyclic voltammetry. Among the samples, 10 wt% Pt@N-doped protein-based carbon exhibits exellent electrochemical performance with a high onset potential of 0.62 V, a high E1/2 of 0.55 V, and a low ΔE1/2= 0.32 mV. Specifically, as compared to the commercial Pt/C, the 10 wt% Pt@N-doped proteinbased carbon had a similar oxygen reduction reaction perfomance and improved electrochemical stability.