Real-Time Quantitative Detection of Ultraviolet Radiation Dose Based on Photochromic Hydrogel and Photo-Resistance

Abstract

Real-time quantitative detection of ultraviolet (UV) radiation dose is vitally important in life and industry. Herein, we report a novel system for real-time quantitative detection and monitoring of UV radiation dose based on photochromic hydrogel and photo-resistance. The UV radiation probe is composed of a UV-responsive poly(N,N-dimethylacrylamide)-ammonium molybdate tetrahydrate hydrogel that rapidly and significantly changes color responding to UV radiation dose, a red filter that instantaneously amplifies the UV-radiation-induced color change signal, and a photo-resistance that instantaneously transforms the color change signal into electric resistance signal. Based on the quantitative relationship between electric resistance and UV radiation dose, real-time quantitative detection of UV radiation dose can be effectively achieved. By further combining the UV radiation probe with a specially designed printed circuit board (PCB), real-time monitoring of UV radiation dose with automatic alarm system is demonstrated for warning and terminating of excessive UV radiation. Such an efficient real-time quantitative detection system for UV radiation dose is highly promising in various applications, such as dermatological treatment, industrial production, and photocatalytic sterilization with UV rays. Furthermore, the proposed strategy provides a universal method to develop novel photodetectors using other photochromic materials and may inspire novel detection and monitoring instruments.

A Series of POM–Viologen Photo-/Electrochromic Hybrids and Hydrogels Acting as Multifunctional Sensors for Detecting UV, Hg2+, and Organic Amines

“…As a new kind of intelligent material, photochromic materials have important applications in the fields of information encryption, optical information storage, photoelectric materials, optical switches, and optical devices . Electron-deficient viologen derivatives (1,1′-disubstituted 4,4′-bipyridiniums), as good photochromic materials, are widely used in ink-free erasable printing, UV detection, and other fields. − It is because of its electron-deficient nature that it can form charge transfer complexes with electron-rich species and has the redox capability of reversible electron transfer under the stimulation of an external environment, such as light. − Therefore, the combination of viologen and multielectron species can construct more color-changing materials with excellent properties.…”

Incorporating Photochromic Viologen Derivative to Unprecedentedly Boost UV Sensitivity in Photoelectrochromic Hydrogel

“…Notably, PAM possesses excellent elastic properties and it returns to its original shape without deformation after continuous stretching, compressing, and folding processes (Figure b). This attribute highlights the promising potential of applying [H 2 L]-SC @PAM in flexible photoelectronic devices. − Intriguingly, the color of [H 2 L]-SC @PAM is initially yellow prior to irradiation, but gradually changes to green upon continuous 365 nm UV irradiation, suggesting that the photochromism of [H 2 L]-SC can be well embedded in the hydrogel (Figure c). For comparison, the color of the PAM gel without incorporating [H 2 L]-SC remains unchanged under the identical irradiation condition (Figure S6).…”

“…Although semiquantification of UV dose can be achieved via a color matching strategy, more accurate quantification based on [H 2 L]-SC and [H 2 L]-SC @PAM replies on a UV–vis absorption spectrophotometer, making them unsuitable for on-site UV dosimetry. , Gratifyingly, the photoinduced coloration of [H 2 L]-SC @PAM is coupled with electrical resistance reduction, which can be utilized for facile and accurate quantification of UV dose via an electric signal . More significantly, the judicious synergy between photochromic [H 2 L]-SC and PAM hydrogel drastically boosts the sensing sensitivity via converting a colorimetric response into an electric signal.…”

“…23,24 Gratifyingly, the photoinduced coloration of [H 2 L]-SC@PAM is coupled with electrical resistance reduction, which can be utilized for facile and accurate quantification of UV dose via an electric signal. 38 More significantly, the judicious synergy between photochromic [H 2 L]-SC and PAM hydrogel drastically boosts the sensing sensitivity via converting a colorimetric response into an electric signal. As shown in Figures S8 and 3d, the resistance of [H 2 L]-SC@PAM decreases linearly in real-time upon UV radiation with a dose rate of 80 mW/cm 2 .…”

Multicolor Luminescence of a Polyurethane Derivative Driven by Heat/Light-Induced Aggregation

“…By exploiting heat/light-induced aggregation, microscopic control of the structure and remote control of the macroscopic luminescence behavior of the material have been realized. Thermochromic/photochromic functional materials exhibit dynamic multicolor fluorescence changes under heat/light stimulation. − Compared with other stimulus-response materials, they have the advantage of contact-less control, − which endows them with great potential applications in the fields of optical response materials, − hologram photography, − encryption, and anticounterfeiting. − There have been some studies on thermo-photoluminescent oligo/polyurethanes, but most of them are composites, such as doping with metal ions, SiO 2 , or rare-earth luminous complexes. − There are also several pure polyurethanes with thermal/photochromic properties obtained by covalent linking or simply doping with monomers that can undergo isomerization. − However, such systems are often plagued by aggregation-caused quenching (ACQ) effects. For example, after gelation, the dense three-dimensional network would impose significant steric hindrance, which makes it challenging to isomerize the chromophores .…”