A new review article in Microchimica Acta finds that smartphone-based optical and spectroscopic sensors show strong potential to decentralize food safety testing across contaminants like pesticides, heavy metals, and pathogens.
Optics is a rising field in spectroscopy, and it is leading to the development of new sensors that are being used for monitoring purposes. In a recent review article presented by a team of researchers at Ho Chi Minh City University of Technology, the researchers examined the evolution of
The food safety analysis field is undergoing several changes. In the review article, the authors document these changes, providing an overview that captures where smartphone-based optical sensors are being deployed and how, as well as address some of the current gaps in optical science.
The main premise of the review article was that conventional laboratory testing for contaminants is accurate but slow, expensive, and centralized, leaving gaps in surveillance at points of production, distribution, and sale.1 It is for this reason that researchers began to consider smartphones as an alternative, and this is logical for several reasons. For one, smartphones are ubiquitous in society, and this trend is not going to abate anytime soon. These devices are carried by billions of users worldwide, and because of their size, they are portable, which is a hot topic in analytical instrumentation as more industries demand smaller devices.1,2
Smartphones combine cameras, processors, connectivity, and app-based interfaces into one device, and this has allowed them to work across four smartphone-adapted sensing modalities, which include colorimetric, fluorescence, chemiluminescence, and
The researchers also examined how hardware additions such as external optics, three-dimensional (3D)-printed attachments, and illumination controls affect measurement accuracy.1 They organized reported applications by contaminant class, including pesticide residues, heavy metals, mycotoxins, food adulterants, microbial pathogens, and spoilage indicators, finding that smartphone-based systems have been demonstrated for detection across all of these categories in laboratory settings.1
There are several current limitations of smartphone-based sensors that are preventing its wider adoption. First, there is currently an absence of standardized protocols for comparing performance across devices and studies.1 Second, there is insufficient testing under the variable and often messy conditions of real food matrices.1 And finally, there is inconsistent integration between smartphone hardware and data-processing software.1
However, with the rise of
The authors concluded that that smartphone-based sensing is shifting from simple, low-cost imaging tools toward more capable analytical instruments.1 This evolution can extend laboratory-grade detection capability into everyday points of food supply chain inspection, from farms and processing facilities to retail and consumer settings.1 However, it is clear from the review article that standardization and validation challenges need to be addressed.
As a result, although the technology shows strong potential for field deployment, it remains held back by a lack of standardization and validation under real-world conditions.1 Future studies are expected to begin to test these sensors under real-world conditions to accelerate its adoption worldwide.
