Ratiometric fluorescent test strips based on CB-Ni²⁺@CDs probes for visual detection of histamine

Histamine is a biogenic amine with various physiological functions. However, excessive consumption of histamine can lead to various symptoms, and pose a threat to human lives. A ratiometric fluorescent test strip for visual detection of histamine was developed based on CB-Ni²⁺@CDs probes. As the concentration of histamine increases, the test strips exhibit a transition in fluorescence signal from yellow-green to blue. The RGB values were extracted from the images, and used for quantitative analysis of histamine. The method had a linear range of 0-1.0 mM, with a detection limit of 0.086 mM. The test strips were employed for the detection of histamine, and the recovery rate was found to be in the range of 88.3% to 104.69%, indicating a high level of accuracy. The uniqueness of the test strips lies in their ability to be produced simply by mixing CB, Ni²⁺ on a suitable polyvinyl alcohol/wood cellulose fiber substrate.