Colorimetric Nano-Biosensor

Switchable linker (antibody) based colorimetric detection using gold nanoparticle aggregation:

• Overall research objectives is to improve sensitivity and selectivity over targets compared to existing colorimetric detection methods.

• Induce gold nanoparticle aggregations using a novel material called “switchable linker” resulting precipitations of gold aggregates which makes it possible to distinguish target concentrations with naked eyes.

• Various pathogens in real food matrix, major peanut allergen, Ara h1 were successfully detected with very low detection limit.

Switchable linker (aptamer) based colorimetric detection using gold nanoparticle aggregation: 

• Swithchable linker based on aptamer has been successfully designed and developed to serve the intended purpose.

• The developed aptasensor has been validated through the detection of E. coli O157:H7, demonstrating its effectiveness and reliability.

• The aptasensor on-site applicability has been confirmed through successful food sample testing, highlighting its practical utility.

Aptamer based label-free colorimetric detection using gold nanoparticle aggregation:

• AuNP are negatively charged due to the adsorbed layer of citrate ions, which stabilizes them through electrostatic repulsion.

• NaCl neutralizes the surface charge of the citrate-covered AuNP, thus causing AuNP to aggregate.

• Aptamer with negative surface charge can bind to the AuNP surface and maintain stability even in salt.

-> AuNP aggregates are formed in the presence of gliadin