Rolling Circle Amplification-based Copper Nanoparticle Synthesis on Cyclic Olefin Copolymer Substrate and Its...

Area of Science:

• Analytical Chemistry
• Biosensing Technology
• Environmental Monitoring

Background:

• Existing methods for diazinon (DZN) detection are often complex and labor-intensive.
• Development of rapid, sensitive, and label-free sensing platforms is crucial for environmental analysis.
• Cyclic olefin copolymer (COC) substrates offer a promising platform for biosensor development.

Purpose of the Study:

• To develop a label-free fluorescent aptasensor for the sensitive detection of diazinon (DZN).
• To utilize rolling circle amplification (RCA) and fluorescent copper nanoparticles (CuNPs) for signal generation.
• To demonstrate the feasibility of using a cyclic olefin copolymer (COC) substrate for this aptasensor.

Main Methods:

• Immobilization of a dual-function (DF) probe and DZN-specific aptamer on a COC 96-well plate.
• Initiation of rolling circle amplification (RCA) triggered by DZN-aptamer complex formation.
• Synthesis of fluorescent copper nanoparticles (CuNPs) using the RCA product as a template for signal detection.

Main Results:

• The aptasensor demonstrated a linear response to DZN concentrations ranging from 0.1 to 3 ppm.
• A low detection limit of 0.15 ppm for DZN was achieved.
• The assay provided a rapid (within 10 min) and sensitive fluorescent signal proportional to DZN concentration.

Conclusions:

• A novel, label-free fluorescent aptasensor based on RCA and CuNPs was successfully developed on a COC substrate.
• The developed sensor offers a simple, rapid, and sensitive method for diazinon detection.
• This approach circumvents the limitations of conventional complex and time-consuming analytical methods.