Handheld SWIR optical reader for monitoring carbon nanotube-based optical sensors

Abstract

Single-walled carbon nanotubes (SWCNTs) are known as highly sensitive biosensors with great potential for both in vitro and in vivo applications1,2,3. SWCNT-based sensors demonstrate inherent photostability, can be tailored to detect a wide range of analytes, and are particularly suited for in vivo applications due to the SWCNT fluorescence emission in the SWIR optical region (900-1700 nm). Long-term animal study after subcutaneous implantation in mice for 400 days4 showed that hydrogel-encapsulated SWCNTs sensors do not cause an inflammatory reaction, nor are they toxic to the animal. This sensor technology is very promising, but until now its application has been limited to research laboratories due to the lack of affordable and portable sensor monitoring equipment. As part of the Innosuisse project NIOXIS, we developed a prototype handheld SWIR reader. The reader consists of an InGaAs imaging camera and circular illumination light source. The fluorescence images of the SWCNT sensors are captured and analyzed using our own developed NIOXIS software. In this study, the feasibility and functionality of the prototype device is presented. The target application of NIOXIS is real-time monitoring of inflammation over longer periods of time and assessment of NO level in joints associated with chronic pathologies.