Portable paper-micro well device composed of agglomerated nano-hematite clusters in enzyme-hydrogel composite for beta glucan detection using smartphone

Abstract

Abstract In present study, we have harnessed the irreplaceable merits of nano-biocomposite biosensing for microfluidic devices preparation. A microfluidic device-prototype (μPADs) with coroneted immobilized enzymes on hematite nanoparticle (αFe2O3NPs) was designed for direct detection of cancer marker β-glucan. Reconfigurable open-smartphone software applications (App) with visual detection and smartphone application can further ease the collection, calculation and display of sensor data on the screen for the biomarker analyte. The bienzymatic-microfluidic analytical devices (Enz-μPADs) with micro-well test-zone were coated with β-glucanase, glucose oxidase, and fenugreek hydrogel stabilized-αFe2O3NPs. Distinct blue color change of as-prepared Enz-μPADs can also be observed by naked eyes and quantified by smartphone App with high accuracy. The smartphone images represented by the saturation parameter of hue–saturation–value (HSV) color space, enables an easy readout of the enzymatic-TMB reaction for β-glucan detection. The linear calibration graph was obtained in the range of 1.0–15 ng mL−1 for standard β-glucan with 0.5 ng mL−1 limit of detection (3 Sb). The practical applicability of Enz-μPADs was tested successfully for anti-cancer dietary-supplements with β-glucan claims. Thus, as-prepared Enz-μPADs with Smartphone-App readout has notable features such as fast colorimetric visual response, low-cost, feasible device bulk production and multiplexity with high specificity and sensitivity.