Simultaneous determination of pH, urea, acetylcholine and heavy metals using array-based enzymatic optical biosensor

Area of Science:

• Biotechnology
• Analytical Chemistry
• Materials Science

Background:

• Simultaneous analysis of multiple analytes in complex samples is challenging.
• Development of specific and sensitive biosensors is crucial for environmental and biological monitoring.
• Array-based biosensors offer potential for multiplexed detection.

Purpose of the Study:

• To fabricate an array-based optical biosensor for simultaneous detection of pH, urea, acetylcholine (ACh), and heavy metals.
• To evaluate the biosensor's specificity, sensitivity, and performance in real samples.
• To demonstrate the application of the biosensor for environmental and biological monitoring.

Main Methods:

• Fabrication of a 50-spot array biosensor using a sol-gel matrix.
• Co-entrapment of urease, acetylcholinesterase (AChE), and FITC-dextran as sensing probes.
• Enzyme inhibition assays for heavy metal detection.
• Testing with environmental and biological samples spiked with metal ions.

Main Results:

• The biosensor achieved simultaneous detection of multiple analytes with high specificity and no cross-interference.
• The system accurately determined pH over a dynamic range of 4-8.5.
• Detection limits for urea and ACh were 2.5-50 microM over 2-3 orders of magnitude.
• Analytical ranges for heavy metals (Cd(II), Cu(II), Hg(II)) were 10 nM to 100 mM.
• Effective screening of enzyme inhibitors in real samples was demonstrated.

Conclusions:

• The developed array-based optical biosensor is highly specific for simultaneous multi-analyte detection.
• The biosensor shows significant potential for application in real-world environmental and biological sample analysis.
• This technology offers a sensitive and reliable platform for monitoring various chemical species and inhibitors.