A paper-based colorimetric point-of-care testing kit using novel two-dimensional CuBO2 nanoplates for the efficient detection of Vitamin C and fabrication of a highly sensitive optical sensor

• Published in: Surfaces and interfaces 2024-12, Vol.55, p.105465, Article 105465
• Main Authors: Radhakrishnan, Malavika, Ravindran, Anjana, Unnikrishnan, Ajaikrishnan, Cheviri, Bineesha, Parambath, Muhammad Javad, Chandran, Neeli, Nair, Swapna Shanmukhan
• Format: Article
• Language: English
• Subjects: 2D materials; 2D-CuBO2; On-spot testing; Optical sensor; Vitamin C colorimetric detection
• ISSN: 2468-0230
• DOI: 10.1016/j.surfin.2024.105465

This work explores the development of a colorimetric on-spot testing kit and the fabrication of an optical sensor to efficiently detect Vitamin C(VC) using novel 2D-CuBO2 nanoplates, a vital marker for health and disease diagnostics. Although CuBO2 exhibits promising properties in various fields, including transparent conducting domains, its application toward sensing remains unexplored. Here, the authors report the primary utilization of 2D- CuBO2 as a potential candidate for sensing, specifically VC. The 2D-CuBO2 is synthesized through a one-pot sol-gel process followed by comprehensive characterization using various analytical techniques. The investigation of the effect of pH on the selective detection of VC was identified to be at a pH of 7. A paper-based sensor and device prototype for the on-spot detection is fabricated, calibrated, and analysed, showcasing the platform's sensitivity and a high degree of selectivity. The development of color can be attributed to the interaction of electromagnetic waves at the surface and interface of VC-modified aggregated CuBO2 nanoplates and, thereby, changes in the surface reflectivity leading to an observable color change. Optical sensing significantly improved the detection limit by several orders (LoD:130 nM) with a linear range of 10 μM to 10 mM. [Display omitted]