No abstract

Directly analyzing an herbal drug and its contamination is crucial to avoid severe problems due to uncertain dosages and unwanted contaminants. This article describes the first example of a dosing-spoon-based sensor for point-of-use detection of an herbal extract and its contamination. Andrographis paniculata is an herbal drug conventionally used for the therapy of many symptoms and infectious diseases, including COVID-19. The developed device consists of a sensitive electrochemical sensor, enabling the detection of A. paniculata extract. The lab-on-a-spoon squarewave voltammetric system provides the detection result with favorable sensitivity and simplicity in a short time (less than 15 s). The calibration curve of the modeled herbal extract covers a range of 0.030–7.350 mg mL–1 with a limit of detection of 20 μg mL–1. The device and data analysis were applied for determining real samples of A. paniculata extracts. The developed device is sensitive for the screening of processed products from A. paniculata. Moreover, this single dosing-spoon-based sensor can also simultaneously screen the contamination of heavy metals (i.e., cadmium and lead). We envision that this lab-on-a-spoon demonstration would expand the scope of portable pharmaceutical and biochemical sensors, offering promising convenient screening tools for industrial and household applications.