Reusable, Robust, and Accurate Laser-Generated Photonic Nanosensor

Ali K. Yetisen, Yunuen Montelongo, Fernando da Cruz Vasconcellos, J.L. Martinez-Hurtado, Sankalpa Neupane, Haider Butt, Malik M. Qasim, Jeffrey Blyth, Keith Burling, J. Bryan Carmody, Mark Evans, Timothy D. Wilkinson, Lauro T. Kubota, Michael J. Monteiro, Christopher R. Lowe

Developing noninvasive and accurate diagnostics that are easily manufactured, robust, and reusable will provide monitoring of high-risk individuals in any clinical or point-of-care environment. We have developed a clinically relevant optical glucose nanosensor that can be reused at least 400 times without a compromise in accuracy. The use of a single 6 ns laser (λ = 532 nm, 200 mJ) pulse rapidly produced off-axis Bragg diffraction gratings consisting of ordered silver nanoparticles embedded within a phenylboronic acid-functionalized hydrogel. This sensor exhibited reversible large wavelength shifts and diffracted the spectrum of narrow-band light over the wavelength range λpeak ≈ 510-1100 nm. The experimental sensitivity of the sensor permits diagnosis of glucosuria in the urine samples of diabetic patients with an improved performance compared to commercial high-throughput urinalysis devices. The sensor response was achieved within 5 min, reset to baseline in ∼10 s. It is anticipated that this sensing platform will have implications for the development of reusable, equipment-free colorimetric point-of-care diagnostic devices for diabetes screening.