Hydrochromic conjugated polymers for human sweat pore mapping

• Published in: Nature communications Vol. 5; no. 1; p. 3736
• Main Authors: Lee, Joosub, Pyo, Minkyeong, Lee, Sang-hwa, Kim, Jaeyong, Ra, Moonsoo, Kim, Whoi-Yul, Park, Bum Jun, Lee, Chan Woo, Kim, Jong-Man
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.04.2014; Nature Publishing Group; Nature Pub. Group
• Subjects: 639/301/1005/1009; 639/638/11; 639/638/455/954; Colorimetry - methods; Fingers - anatomy & histology; Fluorescence; Humanities and Social Sciences; Humans; Molecular Structure; multidisciplinary; Organic solvents; Polyacetylenes - chemical synthesis; Polyacetylenes - chemistry; Polymers; Polymers - chemical synthesis; Polymers - chemistry; Pores; Science; Science (multidisciplinary); Sweat Gland Diseases - diagnosis; Sweat Glands - anatomy & histology; Water - chemistry
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms4736

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. Materials capable of colour changes in response to stimuli are useful in sensors and other applications. Here the authors show a conjugated polymer that rapidly responds to the presence of water, and use it as a sensor to map active sweat pores as a means of fingerprint analysis.