Disposable Paper-on-CMOS Platform for Real-time Simultaneous Detection of Metabolites

Disposable Paper-on-CMOS Platform for Real-time Simultaneous Detection of Metabolites 170 177 IEEE Transactions on Biomedical Engineering (TBME)

Effective early diagnosis of sepsis, and other life threatening diseases, is essential to reducing unnecessary fatalities. A sensitive, robust, portable, and inexpensive biosensing platform capable of combining multiple diagnostic tests into a single device is therefore of major interest for clinical use in diagnosis and treatment monitoring at point-of-care. Paper based sensors are an excellent candidate for widespread deployment of diagnostic or test devices, but the majority of devices today use a simple paper strip to detect only a single marker. For many diseases such as sepsis, one biomarker is not sufficient to make a unique diagnosis. In this work multiple measurements are made on patterned paper simultaneously. Using laser ablation to fabricate parallel microfluidic channels on paper provides a flexible and direct approach for mass manufacture of disposable paper strips. A reusable photodiode array on a complementary metal oxide semiconductor chip is used as the transducer. The system measures changes in optical absorbance in the paper to achieve a system that is capable of multiple simultaneous assays. Known sepsis metabolite biomarkers, glucose and lactate, have been studied and quantified with the platform, achieving sensitivity within the physiological range in human serum. The combination of a low-cost paper strip with microfluidic channels and a sensitive CMOS photodiode sensor array achieves the objective of making a robust, portable and inexpensive biosensing platform using multi-marker panels. The technological innovation we present has the potential to be used in many settings including the home, pharmacy, hospital, ambulance, and field hospital.