A Gelated Colloidal Crystal Attached Lens for Noninvasive Continuous Monitoring of Tear Glucose

Abstract

Abstract:Patients of diabetes mellitus urgently need noninvasive and continuous glucose monitoring in daily point-of-care. As the tear glucose concentration has a positive correlation with that in blood, the hydrogel colloidal crystal integrated into contact lens possesses promising potential for noninvasive monitoring of glucose in tears. This paper presents a new glucose-responsive sensor, which consists a crystalline colloidal array (CCA) embedded in hydrogel matrix, attached onto a rigid gas permeable (RGP) contact lens. This novel sensing lens is able to selectively diffract visible light, whose wavelength shifts between 567 and 468 nm according to the alternation of the glucose concentration between 0 and 50 mM and its visible color change between reddish yellow, green, and blue. The detection limit of responsive glucose concentration can be reduced to 0.05 mM. Its combination with a contact lens endows it with excellent biocompatibility and portability, which shows great possibility for it to push the development of glucose-detecting devices into new era.

Hydrogel-Based Colloidal Photonic Crystal Devices for Glucose Sensing

“…A prototype of such a lens is shown in Figure 6D. Figure 6E states the diffraction wavelength shift at a relatively low glucose concentration [93]. Figure 6.…”

“…(D) Diagram and photograph (insert) of a HCPC contact lens [6]. (E) The response of a PVA HCPC contact lens at low glucose concentration; insert shows a photograph of the color changed lens sample [93]. Figure 6.…”

Lab on the eye: A review of tear-based wearable devices for medical use and health management

“…Several teams developed contact lenses embedded with fluorescent nanoparticles or boronic acid-containing fluorophores to obtain the glucose concentration by measuring the fluorescence intensity and resonance energy transfer. More recently, a colloidal crystal array (CCA) contact lens was able to selectively detect a visible color change reflecting variation in the glucose concentration (30).…”

Selective and Colorimetric Detection of p-Nitrophenol Based on Inverse Opal Polymeric Photonic Crystals

“…Photonic crystals, consisting of periodic arrangements of dielectric materials with different refractive indexes, produce color when the photonic stop bands are located in the visible range [9][10][11][12][13][14][15][16][17][18]. Because the response process of photonic crystals can be directly expressed by light diffraction signals (the structure color "naked eye" can be seen) without any marking technology or any other analytical instruments, much attention has been paid to it in the field of sensor design and application [19][20][21][22][23][24][25][26][27][28][29][30][31]. In a previous work we prepared a novel carbonate ion sensor for detection of carbonate ions by the naked eye based on inverse opal polymeric photonic crystals (IOPPCs) [32].…”