5,10,15,20-Tetrakis(4-carboxyl phenyl)porphyrin–CdS nanocomposites with intrinsic peroxidase-like activity for glucose colorimetric detection

•H2TCPP–CdS nanocomposites were synthesized by a facile one step under mild condition.•H2TCPP–CdS nanocomposites possess excellent intrinsic peroxidase-like activity.•A sensitive and selective colorimetric sensor for glucose is provided based on H2TCPP–CdS nanocomposites.•The generation of hydroxyl radical (·OH) decomposed from H2O2 is contributed to efficient catalytic.

Here, we describe the design of a novel mimic peroxidase, nanocomposites composed by 5,10,15,20-tetrakis(4-carboxyl phenyl)-porphyrin (H2TCPP) and cadmium sulfide (CdS). The H2TCPP–CdS nanocomposites can catalyze oxidation of substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2 and form a blue product which can be seen by the naked eye in 5 min. The mechanism of the catalytic reaction originated from the generation of hydroxyl radical (·OH), which is a powerful oxidizing agent to oxidize TMB to produce a blue product. Then, we developed a colorimetric method that is highly sensitive and selective to detect glucose, combined with glucose oxidase (GOx). The proposed method allowed the detection of H2O2 concentration in the range of 4 × 10− 6–1.4 × 10− 5 M and glucose in the range of 1.875 × 10− 5–1 × 10− 4 M with detectable H2O2 concentration as low as 4.6 × 10− 7 M and glucose as low as 7.02 × 10− 6 M, respectively. The results provided the theoretical basis of practical application in glucose detecting and peroxidase mimetic enzymes.

Graphical abstract5,10,15,20-tetrakis(4-carboxyl phenyl)-porphyrin (H2TCPP)–CdS nanohybrids were demonstrated to possess intrinsic peroxidase-like activity and used for a glucose colorimetric sensor.Figure optionsDownload full-size imageDownload as PowerPoint slide