A simple and inexpensive thermal optic nanosensor formed by triblock copolymer and polydiacetylene mixture

•Polydiacetylene (PDA)/triblock copolymer (TC) mixture formed an optical nanosensor.•PDA/TC nanoblend was more sensitive to temperature change than PDA vesicle.•PDA/TC nanosensor detected temperature change in a wider range than PDA vesicle.•TC and diacetylene properties affected thermochromism behavior of PDA/TC nanoblend.•PDA/TC nanoblend shows applicability as thermosensor for food industry.

Polydiacetylene (PDA) vesicles have been applied as optical sensors in different areas, although there are difficulties in controlling their responses. In this study, we prepared nanoblends of PDA with triblock copolymers (TC) as a better sensor system for detecting temperature change. The influences of diacetylene (DA) monomer, and the TC chemical structure and concentration on the colorimetric response (CR) were examined. The TC/PDA nanoblend was remarkably more sensitive to temperature change, than classical vesicles. A higher L64 concentration of 12.0% (w/w) reduced the chromatic transition temperature (Ttr) to as low as 24 °C. When using different TCs, the Ttr values can be ordered as L35 < F68< L64 < F127