Sensing properties of chitosan and chitosan-roselle film sensors on toluene concentrations detection

Abstract

This study aims to observe the sensing properties of chitosan sensor (CS) and chitosanroselle sensors (CRSs) on toluene at various concentrations. CRSs were deposited using various chitosan: roselle ratio of 99:1 to 89:11 to find the optimum ratio which exhibit the best electrical properties. Toluene is a suitable chemical marker for lung cancer diagnosis where 30 ppb toluene in exhaled breath is regarded to be a distinctive early symptom of lung cancer. Therefore, the preliminary study on the electrical laboratory testing of the CS and CRSs film properties to toluene vapor-contaminated air in the range of 15–90 ppb was carried out at room temperature (25–30oC). The results suggested that the proposed CS and CRS can operate at room temperature with a high performance demonstrated by good response, recovery, sensitivity, repeatability, stability and selectivity. All CRS exhibited better output voltage compared to CS where the optimum ratio observed was chitosan:roselle (93:7). This is a good preliminary step for a trouble free, painless and steadfast technique which aid in diagnosing lung cancer, enabling early detection.