Volatile Organic Compounds (VOCs) are commonly used in various industries, but they can be toxic and pose significant health risks, primarily affecting the respiratory system and contaminating groundwater. As a result, there is growing interest in developing reliable sensors for monitoring VOCs. This study presents a convenient and straightforward sensor that utilizes cholesteric liquid crystals (CLCs) for quantitatively detecting volatile organic solvents. Our results demonstrate the performance of two cholesteric liquid crystal sensors, CLC1 and CLC2, across varying concentrations and temperatures. CLC1 exhibited the fastest response times, with the R color channel achieving the shortest response of 5.4 s and the highest linear correlation, particularly at elevated temperatures (27–30 °C). Ethanol was also evaluated within a similar operating window, but it produced a measurable yet weaker optical response than acetone under controlled temperature conditions, requiring a broader concentration range to capture the dynamic response prior to signal saturation. In contrast, CLC2 performed optimally in the G color channel for acetone detection, showing the most consistent and reliable linearity across 21–24.5 °C. These findings underscore the significant influence of volatile organic solvents and temperature on sensor performance and confirm that specific optical channels (R for CLC1, G for CLC2) are most suitable for quantitative, liquid-phase detection. • CLCs enable rapid, real-time VOC solvent detection and customizable sensor design. • CLC1 (red) showed strongest linearity and fastest response at 27–30 °C. • CLC2 (green) exhibited best stability and sensitivity at 21–24.5 °C. • Temperature increase enhanced response speed and detection performance. • Findings guide tailored CLC design for VOC sensing across environments.
Jhang et al. (Sun,) studied this question.