Portable immuno nano biosensor for multiple disease detection using 3D printed SPR technologies

Abstract

The role of biosensors as point-of-care devices is well explored in recent years and their usage in the current market has been highly increased after the outbreak of the COVID pandemic. The point-of-care devices generally use sensing principles of electrochemical, immune fluorescence, microbial and electromagnetic. The sensor we developed uses the phenomenon of Surface Plasmon resonance with optic fiber technology which is a novel design to implement in point-of-care devices. With the latest innovations and improvements in 3D printing technologies the development and prototyping of these POC devices have been accelerated to the greatest potential. Here the entire device was prototyped using Creality Upgraded Ender 3 2021 model 3D printer where the 3D files were sliced in Ultimaker Cura software and printed with PLA filament by fused filament deposition modeling (FFDM). The device has a USB light and camera source on either side of the sensing chamber and a cassette with optic fiber coated with respective antibodies as a sensing platform. The device is connected to respective USB ports and introduced with the sample over a cassette and placed in the reaction chamber. The reaction occurs spontaneously which is captured by the webcam and recorded by the software. We tested the bare sensor with increased concentrations of glycerol after coating it with a silver mirror by a standard reproducible method of Tollens silver mirror. The sensor showed the best sensitivity with increasing concentrations of glycerol. The sensor also immobilized with target antibodies of pLDH parasite lactate dehydrogenase by non-specific binders just by adding target bio-analyte and receptor over silver mirror functionalized surface and tested with positive control antigen of malaria parasite antigen. The sensor showed the highest sensitivity at 50X concentration of antigen and least at 10x concentration stating maximum and minimum values for a limit of detection. This device using this principle could has wide functionalities to detect multiple biological samples by changing the antibodies to our respective analyte over the reaction chip for multiple times with low cost.