Hydrogel gratings with patterned analyte responsive dyes for spectroscopic sensing

Abstract

This is an unprecedented report of hydrogel gratings with an analyte responsive dye immobilised in alternating strips where the patterned dye is its own dispersive element to perform spectroscopic sensing.

Reflective leaky waveguide gratings (LWGs) with internal referencing for sensing

“…This reduction in sensitivity of differential measurements may be because not all the PC-biotin could be removed after 10 min exposure to the IL set-up. 51 This means that the distribution of biotin/streptavidin complex in strips exposed to high and low intensity fringes of the IL set-up was low and high, respectively, but not 0 and 100%. Thus, biotin-protein A and IgG could bind to both types of strips, reducing the differential sensitivity.…”

“…This cosinusoidal distribution of PC-biotin was verified by fluorescence imaging of fluorescein isothiocyanate bound to the freed amines. 51 Thus, the η m of LWGs can be estimated by eqn (4). However, unlike transmission gratings, LWGs are illuminated with a range of angles of incidence and the phase of light reflected from strips without and with streptavidin is a function of angle of incidence.…”

“…Hydrogel gratings have been used to sense a wide variety of analytes including microorganisms, 1 proteins, [2][3][4][5] glucose, 6 pH, 7,8 metal ions, 9,10 and volatiles. 11,12 In comparison to other label-free optical sensors, [13][14][15] hydrogel gratings can provide more effective referencing because sensor and reference regions are closely spaced.…”

Photoactive hydrogels for pre-concentration, labelling, and controlled release of proteins

“…The reaction schemes were adapted from the procedure reported by Landfester and Klinger 40 and our previous work. 41,42 The details of reaction and purification conditions of monomers along with characteristic shifts in their NMR spectra are provided in the ESI. †…”