Sensors and Actuators Reports (Nov 2022)
Colorimetric Visual Sensors for Point-of-needs Testing
Abstract
The concept of color in chemistry can take us back to when the separation of color-based natural products, dyes, and other chemical compounds led to the technique called chromatography. The fundamental color-based chemical separation opened the modern ultra-speed, ultra-resolution chromatographic methods used for all analytical purposes in chemistry, biology, nanotechnology, and materials science today. The same color property of molecules either directly available or that can be created through indirect secondary chemical and biochemical reactions have led to the development of colorimetric sensors. More than ever before the need for user-friendly molecular diagnostics and on-site chemical analysis has been well recognized for their lifesaving roles in the pandemic era. The objective of this review article is to share some representative recent developments on colorimetric approaches for molecular diagnostics of relevance to viruses, food safety, disease diagnostics and management, and environmental analysis. Attention to the purpose of the sensor designs, rationale, and mechanistic aspects of the approaches are covered, and the demonstration of applicability for real sample analysis in each cited literature report is reviewed. Our scientific community should consider mandating sensor research reports to explicitly disclose the following key sensor attributes right in the abstract paragraph: (i) real sample evaluations, (ii) sample pretreatments, sample matrix dilutions, and their durations, (iii) differences in the analytical performance of isolated samples and complex real sample matrices, and (iv) robust independent validation/correlation methods to assess the fit-for-purpose of the sensor.
