Amperometric biosensor for the quantification of gentisic acid using polyphenol oxidase modified carbon paste...

Area of Science:

• Biochemistry
• Enzymology
• Analytical Chemistry

Background:

• Acetyl salicylic acid (ASA) is a common drug with various metabolites.
• Polyphenol oxidase (PPO) enzymes are involved in various biological processes.
• Selective detection of drug metabolites is crucial for therapeutic drug monitoring.

Purpose of the Study:

• To investigate the affinity of mushroom polyphenol oxidase (PPO) for gentisic acid (GA).
• To develop a selective detection method for GA in the presence of ASA and its derivatives.
• To characterize the electrochemical sensing performance of PPO for GA.

Main Methods:

• Spectrophotometry was used to assess enzyme-ligand interactions.
• Electrochemical techniques were employed for quantitative analysis.
• Eadie-Hofstee plots were utilized for kinetic parameter determination.

Main Results:

• Mushroom PPO exhibits significant affinity for GA.
• The enzyme selectively recognizes GA over ASA, salicylic acid (SA), and salicyluric acid (SUA).
• Electrochemical detection achieved a sensitivity of (6.1+/-0.1)x10(4) NAM(-1) at -0.150 V, with a linear response up to 2.0x10(-4) M and a detection limit of 5.0x10(-5) M.

Conclusions:

• Mushroom PPO is a suitable candidate for the selective electrochemical detection of GA.
• The developed method demonstrates high sensitivity and selectivity for GA.
• This finding has potential applications in the analysis of ASA metabolism.