Reversible chromatic sensor fabricated by inkjet printing TCDA-ZnO on a paper substrate

•Use 10,12-tricosadiynoic acid (TCDA) as PDA monomer.•Use inkjet printing method to fabricate poly-TCDA/poly-TCDA-ZnO thin films.•Use conventional paper as substrate.•Incorporate poly-TCDA/poly-TCDA-ZnO into QR code.

A flexible reversible color change poly-(10,12-tricosadiynoic acid) TCDA-ZnO (2.5 wt%) composite based chromatic sensor was successfully designed and fabricated by inkjet printing. Fabricated sensors showed good reversibility and stable chromatic properties with color transition temperature at 70 °C. Attenuated Total Reflection (ATR) – Fourier Transform Infrared (FTIR) spectra show chelate formation between TCDA and ZnO. Temperature-dependent Raman spectra indicate that the blue-red phase of poly-TCDA-ZnO (2.5 wt%) is thermally triggered at 70 °C and the amorphous phase is formed near 120 °C. An inkjet printed Quick Response (QR) code using poly TCDA-ZnO demonstrates a sensory functionality which can be incorporated in these codes.