Fluorescence Imaging (FI) is a powerful technique in biological science and clinical medicine. Current FI devices that are used either for in-vivo or in-vitro studies are expensive, bulky and consume substantial power, confining the technique to laboratories and hospital examination rooms. Here we present a miniaturised wireless fluorescence endoscope capsule with low power consumption that will pave the way for future FI systems and applications. With enhanced sensitivity compared to existing technology we have demonstrated that the capsule can be successfully used to image tissue autofluorescence and targeted fluorescence via fluorophore labelling of tissues. The capsule incorporates a state-of-the-art complementary metal oxide semiconductor single photon avalanche detector imaging array, miniaturised optical isolation, wireless technology and low power design. When in use the capsule consumes only 30.9 mW, and deploys very low-level 468 nm illumination. The device has the potential to replace highly power-hungry intrusive optical fibre based endoscopes and to extend the range of clinical examination below the duodenum. To demonstrate the performance of our capsule, we imaged fluorescence phantoms incorporating principal tissue fluorophores (flavins) and absorbers (haemoglobin). We also demonstrated the utility of marker identification by imaging a 20 μM fluorescein isothiocyanate (FITC) labelling solution on mammalian tissue.

Complementary metal oxide semiconductor (CMOS) technology has made personal mobile computing and communications an everyday part of life. In this paper we present a nanophotonic integrated CMOS-based biosensor that will pave the way for future personalized medical diagnostics. To achieve our aim, we have monolithically integrated plasmonic nanostructures with a CMOS photodiode. Following this approach of monolithic nanophotonics–microelectronics integration, we have successfully developed a miniaturized nanophotonic sensor system with direct electrical readout, which eliminates the need of bulky and costly equipment that is presently used for interrogation of nanophotonic sensors. The optical sensitivity of the plasmonic nanostructures is measured to be 275 nm/refractive index unit (RIU), which translates to an electrical sensitivity of 5.8 V/RIU in our integrated sensor system. This advance is the first demonstration of monolithic integration of nanophotonic structures with CMOS detectors and is a crucial step toward translating laboratory based nanophotonic sensing systems to portable, low-cost, and digital formats.

Precision metabolomics and quantification for costeffective, rapid diagnosis of disease are key goals in personalized medicine and point-of-care testing. Presently, patients are subjected to multiple test procedures requiring large laboratory equipment. Microelectronics has already made modern computing and communications possible by integration of complex functions within a single chip. As More than Moore technology increases in importance, integrated circuits for densely patterned sensor chips have grown in significance. Here, we present a versatile single CMOS chip forming a platform to address personalized needs through on-chip multimodal optical and electrochemical detection that will reduce the number of tests that patients must take. The chip integrates interleaved sensing subsystems for quadruplemode colorimetric, chemiluminescent, surface plasmon resonance and hydrogen ion measurements. These subsystems include a photodiode array and a single photon avalanche diode array, with some elements functionalized to introduce a surface plasmon resonance mode. The chip also includes an array of ion sensitive field effect transistors. The sensor arrays are distributed uniformly over an active area on the chip surface in a scalable and modular design. Bio-functionalization of the physical sensors yields a highly selective simultaneous multiple-assay platform in a disposable format. We demonstrate its versatile capabilities through quantified bioassays performed on-chip for glucose, cholesterol, urea and urate, each within their naturally occurring physiological range.

Elevated cholesterol levels are associated with a greater risk of developing cardiovascular disease and other illnesses, making it a prime candidate for detection on a disposable biosensor for rapid point of care diagnostics. One of the methods to quantify cholesterol levels in human blood serum uses an optically mediated enzyme assay and a bench top spectrophotometer. The bulkiness and power hungry nature of the equipment limits its usage to laboratories. Here, we present a new disposable sensing platform that is based on a complementary metal oxide semiconductor process for total cholesterol quantification in pure blood serum. The platform that we implemented comprises readily mass-manufacturable components that exploit the colorimetric changes of cholesterol oxidase and cholesterol esterase reactions. We have shown that our quantification results are comparable to that obtained by a bench top spectrophotometer. Using the implemented device, we have measured cholesterol concentration in human blood serum as low as 29 µM with a limit of detection at 13 µM, which is approximately 400 times lower than average physiological range, implying that our device also has the potential to be used for applications that require greater sensitivity.