RT Journal Article SR Electronic T1 Chitozyme: First Peroxidase-like Activity of Chitosan for Multiplexed Visual Detection of H2O2, Glucose and Lactate on Paper-based Device JF bioRxiv FD Cold Spring Harbor Laboratory SP 162446 DO 10.1101/162446 A1 Syed Rahin Ahmed A1 Xuan Weng A1 Suresh Neethirajan YR 2017 UL http://biorxiv.org/content/early/2017/07/12/162446.abstract AB Visual read-out diagnostics tools are promising candidates for field applicable medical devices. Current colorimetric biosensors require introduction of natural enzymes or nanozymes, which has some serious drawbacks for practical applications. Chitosan, a natural polymer, provides safe and efficient compound in medical and pharmaceutical technology. Herein, we report on a simple, cost-efficient, field-portable, environmental friendly and ultra-sensitive multiplex detection platform based on peroxidase-like activity of chitosan in the presence of 3,3’,5,5’-Tetramethylbenzidine (TMBZ) and H2O2. This straight forward signal amplification strategy was successfully applied to detect H2O2, glucose and lactate with the limit of detection (LOD) of 2.64 pM, 0.104 μM and 2.8 nM respectively, represents the lowest LOD of H2O2, glucose and lactate with visual read-out. The chitosan-based assay performance was also retained in complex biological media for glucose and lactate detection. Furthermore, the proposed assay was successfully demonstrated as a paper-based colorimetric biosensor. Most importantly, the simplicity, biocompatibility and sensitivity of the proposed assay will open new doors for instrument free naked eye visual detection of H2O2, glucose and lactate detection.