Challenges and proposed solutions for optical reading on point-of-need testing systems

SCHAUMBURG, FEDERICO; BERLI, CLAUDIO L. A.

Frontiers in Sensors

Frontiers Media SA

Año: 2023 vol. 4

A broad spectrum of application fields, including human and animal health, foodsafety and environmental monitoring, require performing real time, on-fieldchemical determinations, a concept known as point-of-need testing (PONT).In the case of infectious diseases, it allows for early diagnosis, which usuallyenables better treatment options for the patient, and permits early outbreakdetection and intervention with proper control measures. PONT solutions areusually developed on microfluidic chips, preferably with no extra equipment, as tolower their cost, ease their delivery and portability. However, equipment-freePONT is not always feasible, since off-chip operations (e.g., pumping or heating)might be required and provided by the so-called analyzers. A typical example is thehardware for optical reading, which is the subject of this perspective article. Firstly,the state-of-the-art is briefly analyzed considering the solutions provided by bothacademy and industry. Special emphasis is made on the smartphone-basedapproaches that use no additional hardware (add-ons) for optical reading.Smartphones are the straightforward option, since they can replace a numberof operations typically done by analyzers. The issues arising from usingsmartphones without add-ons are classified into variability sources andtechnical challenges. Finally, a set of methods for dealing with thesechallenges is proposed and briefly discussed. Simpler systems will be moreeasily adopted by more users, for a broader range of application cases, and willlet PONT be a more powerful tool for improving disease diagnosis and outbreakmanagement.