Holographic Glucose Sensors

Abstract

Rapid glucose sensors have applications in the screening, diagnosis and monitoring of diabetes at point of care. This chapter demonstrates the design, fabrication and clinical trial of reusable holographic glucose sensors. Holographic sensors comprised boronic acid derivative functionalised acrylamide matrices, which consisted of Bragg diffraction gratings that colorimetrically report on the concentration of glucose in aqueous solutions. The optical properties of the sensor were designed and characterised by computational analysis. The sensors were fabricated by combining the advantages of multi-beam interference and in situ size reduction of silver metal (Ag0) nanoparticles (NPs) by single-pulse laser writing. Fully-quantitative narrow-band (monochromatic) readouts were attained through spectrophotometry. The advantages of holographic sensors over other sensing mechanisms are (i) reusability, (ii) amenable to mass manufacturing through laser writing, (iii) readouts in visible as well as near-infrared regions of the spectrum, and (v) reproducibility to sense glucose concentrations up to 400 mM using a low sample volume (<500 μl). Interference due to other metabolites such as lactate and fructose was also evaluated. Trials of the sensor in the urine samples of diabetic patients demonstrated that the sensor had improved performance as compared to Multistix® 10 SG read by CLINITEK Status®, while having comparable performance with fully-automated Dimension® Clinical Chemistry System. Holographic glucose sensors may have clinical applicability for diabetes screening or diagnosis of bacterial urinary tract infections.