Tuning annealing temperature to improve the sensing performance of single-walled carbon nanohorn-modified electrodes for simultaneous detection of ascorbic acid, dopamine, and uric Acid

Background: Ascorbic acid (AA), dopamine (DA), and uric acid (UA) are essential biomolecules in the human body, and abnormal concentrations can impact overall health. Therefore, developing a highly sensitive sensor capable of simultaneously detecting these three substances is crucial for disease prevention. Methods: In this study, single-walled carbon nanohorns (SWCNHs) were heat-treated at different annealing temperatures (200 °C-1200 °C) and modified onto a glassy carbon electrode (GCE) for the simultaneous detection of AA, DA, and UA. The influence of annealing temperature on the surface properties of SWCNHs and their sensing performance was thoroughly analyzed. Significant findings: Among them, SWCNHs annealed at 1200 °C exhibited more defects, enhancing the electrochemically active surface area and significantly improving detection performance. The 1200-SWCNH/GCE electrode demonstrated excellent peak separation. It showed a 3.3-, 3.6-, and 4.0-fold increase in sensitivity compared to the non-annealed electrode, with sensitivities of 0.078 μM/μA, 2.010 μM/μA, and 0.572 μM/μA for AA, DA, and UA, respectively. Additionally, this sensor demonstrated outstanding selectivity, reproducibility, and repeatability. In real sample analysis, the recovery rates for AA, DA, and UA ranged from 99.05 % to 104.03 %, validating the feasibility of 1200-SWCNH/GCE for practical applications.