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.

5,10,15,20-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 as PowerPoint slide