Nanomaterial Based Electrochemical Sensing Systems Toward Catechol Detection

Date

2024-6-14

Author

Öncü, Sepren

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Catechol, also known as pyrocatechol, is an organic phenolic compound. Monitoring catechol is crucial due to its low degradability and toxicity. Various methods, including liquid and gas chromatography and spectrophotometry, have been used to detect catechol. The impracticality of real-time monitoring is due to high cost, time consumption, and simple pretreatment required by these classical methods. Laccase based biosensors have become popular due to their ability to detect highly toxic environmental substances. This thesis aimed to fabricate two different nanomaterial based laccase biosensors for the determination of catechol. In the first study, a new nanocomposite called Chit-AgNPs was synthesized using a chemical reduction method. This nanocomposite was applied as a coating on the graphite electrode surface, serving as a matrix to immobilize the Lac enzyme. Then, amperometric measurements conducted resulted in with LOD of 3.85 μM, LOQ of 12.71 μM with LDR of 5-250 μM for the GE/Chit-AgNPs/Lac biosensors. Results showed that the biosensor is able to detect catechol in tap water and wine samples. In the second study, newly synthesized conjugated polymer nanoparticles (P-PBF NP) were used as a matrix for the Lac enzyme via the reprecipitation method. The nanoparticles were successfully modified on graphite electrodes, followed by laccase immobilization. Amperometric measurements conducted resulted in with LOD of 0.49 μM, LOQ of 1.48 μM with LDR of 0.5-25 μM for the GE/P-PBF NP/Lac biosensors. The biosensor demonstrated good sensitivity in detecting catechol in tap water and green tea samples.

Subject Keywords

Electrochemical Laccase Biosensors, Conjugated Polymer Nanoparticles, Chitosan, Silver Nanoparticles, Catechol

URI

https://hdl.handle.net/11511/110395

Collections

Graduate School of Natural and Applied Sciences, Thesis