Hydrochromic conjugated polymers for human sweat pore mapping

Abstract

Hydrochromic materials have been actively investigated in the context of humidity sensing and measuring water contents in organic solvents. Here we report a sensor system that undergoes a brilliant blue-to-red colour transition as well as ‘Turn-On’ fluorescence upon exposure to water. Introduction of a hygroscopic element into a supramolecularly assembled polydiacetylene results in a hydrochromic conjugated polymer that is rapidly responsive (<20 μs), spin-coatable and inkjet-compatible. Importantly, the hydrochromic sensor is found to be suitable for mapping human sweat pores. The exceedingly small quantities (sub-nanolitre) of water secreted from sweat pores are sufficient to promote an instantaneous colorimetric transition of the polymer. As a result, the sensor can be used to construct a precise map of active sweat pores on fingertips. The sensor technology, developed in this study, has the potential of serving as new method for fingerprint analysis and for the clinical diagnosis of malfunctioning sweat pores.

Multi-color Reversible Photochromisms via Tunable Light-Dependent Responses

“…Smart materials that show reversible optical responses to different chemical and physical stimuli have led to the development of numerous optical devices finding wide applications as sensors, [1][2][3] security devices, 4,5 smart windows, 6,7 and information displays. [8][9][10][11] The stimuli sources including pH, 12 electricity, 13 temperature, 14 solvent, 15 mechanical deformation, 16 and light 17 show promise as external stimuli to control the response of the materials in both liquid and solid phases.…”

Novel organic–inorganic hybrid powder SrGa12O19:Mn2+–ethyl cellulose for efficient latent fingerprint recognitionviatime-gated fluorescence

“…Fingerprint recognition is the most reliable method to identify a person because of the unique characteristics of each ngerprint. [1][2][3] There is an urgent need for an efficient and easy ngerprint identication method in many elds such as forensic investigation, 4,5 law enforcement, 5,6 and medical diagnostics. 7 Generally, latent ngerprints (LFPs) can be visualized by creating a strong optical contrast between the surface of the ngerprint ridges and the ngerprint grooves.…”

Fluorescence sensor for water based on PET (photo-induced electron transfer): Anthracene-bis(aminomethyl)phenylboronic acid ester

“…[5][6][7][8][9][10][11][12][13] However, this fluorescence quenching system makes it difficult to detect trace amounts of water. Thus, recently, some research groups reported the fluorescence enhancement system [1][2][3][4][13][14][15] based on decomposition reaction [14] and spirolactone ring opening reaction [15] of sensor, or metal-organic framework. [2] On the other hand, the fluorescence sensors based on photo-induced electron transfer (PET) concept have been generally developed for detecting cations such as H + , Na + , K + , Ca 2+ , Mg 2+ , Cu 2+ , Zn 2+ , Pb 2+ , and Cd 2+ as well as neutral organic species in biochemical analyses.…”

“…IR recorded on a Perkin Elmer Spectrum One FT-IR spectrometer by ATR method.Absorption spectra were observed with a Shimadzu UV-2910 spectrophotometer.Fluorescence spectra were measured with a Hitachi F-4500 spectrophotometer 1. H NMR spectra were recorded on a Varian-400 (400 MHz) FT NMR spectrometer.…”