A Portable Nanoporous Gold Modified Screen-Printed Sensor for Reliable and Simultaneous Multi-Vitamins Analysis

Abstract

Despite being present in minimal amounts, vitamin B2 (VB2), vitamin C (VC), and vitamin B6 (VB6) each play indispensable roles in human metabolisms. Given that VB2, VC, and VB6 cannot be synthesized by the human body, detections of these three vitamins both in fermentation liquid where vitamins are industrially manufactured and in human serum where vitamin concentrations could be clinically controlled are of significant importance. Here, a nanoporous gold (NPAu) modified screen-printed electrode (NPAu/SPE) was fabricated to detect VB2, VC, and VB6 based on NPAu’s electro-oxidation towards vitamins. Owing to the wide separation of peak potentials among VB2, VC, and VB6, the simultaneous detection of these three vitamins was achieved by the NPAu/SPE within a potential range from −0.8 V to 0.8 V. The achieved limits of detection (LOD) for VB2, VC, and VB6 were 0.46, 6.44, and 1.92 μM, with sensitivities of 68.58, 4.77, and 15.94 μA/μM, respectively. Subsequent reliability experiments suggested that the NPAu/SPE exhibited solid anti-interference capability and repeatability. Additionally, the real-sample detection of the NPAu/SPE towards VB2, VC, and VB6 was achieved both in human serum and in fermentation liquid with comparable accuracy (the recovery rates were from 89.8% to 111.7%) as high-performance liquid chromatography (HPLC). Moreover, the portable NPAu/SPE showed comparable performance in terms of the LOD and linear dynamic range when compared to glassy carbon electrodes (GCE) limited to laboratory detection. The proposed NPAu/SPE possesses various advantageous properties including portability, easy fabrication, high sensitivity, and cost-efficiency, making it a potential candidate for clinical and industrial multi-vitamins analysis.