Detection of iprobenfos and edifenphos using a new multi-aptasensor

Area of Science:

• Analytical Chemistry
• Biosensor Technology
• Environmental Science

Background:

• Accurate detection of pesticide residues like iprobenfos (IBF) and edifenphos (EDI) is crucial for food safety and environmental monitoring.
• Existing detection methods may lack sensitivity, selectivity, or on-site applicability for agricultural settings.
• Aptasensors offer a promising alternative due to their high specificity and potential for miniaturization.

Purpose of the Study:

• To develop and validate a novel aptamer-based colorimetric multi-aptasensor for the sensitive and selective detection of iprobenfos (IBF) and edifenphos (EDI).
• To evaluate the performance of the developed aptasensor in real agricultural samples, specifically spiked rice.
• To explore the potential of the aptamer as a bioreceptor for other sensing applications.

Main Methods:

• Development of a multi-target aptasensor utilizing aptamer EIA2.
• Characterization of aptamer binding affinities using isothermal calorimetry assays.
• Validation of selectivity using gold nanoparticle (AuNP) assays.
• Implementation and accuracy assessment in spiked paddy and polished rice samples.

Main Results:

• The multi-aptasensor achieved sensitive detection of iprobenfos (IBF) and edifenphos (EDI) within the range of 10 nM to 5 nM, respectively.
• Isothermal calorimetry revealed dissociation constants of 1.67 μM for IBF and 38 nM for EDI.
• The aptasensor demonstrated high accuracy, with accuracies around 80% in paddy rice and 90% in polished rice samples.

Conclusions:

• The developed aptamer-based colorimetric multi-aptasensor provides a sensitive, selective, and accurate method for detecting iprobenfos (IBF) and edifenphos (EDI).
• This aptasensor is suitable for on-site pesticide detection in agricultural fields as a point-of-care (POC) tool.
• The aptamer EIA2 shows potential as a versatile bioreceptor for constructing other types of aptasensors.