Related Experiment Video
Updated: Aug 6, 2025
07:08
A Rapid, Multiplex Dual Reporter IgG and IgM SARS-CoV-2 Neutralization Assay for a Multiplexed Bead-Based Flow Analysis System
Published on: April 6, 2021
5.1K
Bifunctionalized nanobioprobe based rapid color-shift assay for typhoid targeting Vi capsular polysaccharide
Megha Choudhary1, Bhawana Bisht2, Jai Kumar Saini1
1Council of Scientific and Industrial Research (CSIR), Institute of Microbial Technology (IMTECH), Sector 39-A, Chandigarh, 160036, India.
Biosensors & Bioelectronics
|March 17, 2023
Summary
A new rapid typhoid fever diagnostic assay uses a novel nanobioprobe for accurate detection. This color-shift assay offers 100% sensitivity and results within 15 minutes, addressing current diagnostic challenges.
Area of Science:
- Nanotechnology
- Biomedical Diagnostics
- Microbiology
Background:
- Typhoid fever, caused by Salmonella Typhi, suffers from diagnostic inaccuracies leading to antibiotic overuse.
- Current diagnostic methods have limitations, creating a gap in timely and precise identification of the illness.
Purpose of the Study:
- To develop a rapid, sensitive, and specific diagnostic assay for typhoid fever.
- To create a novel bifunctional nanobioprobe for enhanced detection of Salmonella Typhi biomarkers.
Main Methods:
- A bifunctional nanobioprobe (Vi-AgNP) functionalized with Vi polysaccharide and silver (Ag) was synthesized.
- The assay utilizes immunoreactions and urease activity for a color-shift output, visualized with HRTEM and validated using microscale thermophoresis (MST).
Main Results:
- The Vi-AgNP probe demonstrated high binding efficiency with a low dissociation constant (Kd) of 437 nM when interacting with urease in the presence of antibodies.
- The assay achieved 100% sensitivity in validating with 53 human sera samples, with a relative standard deviation (RSD) of 4.3%.
Conclusions:
- The developed rapid color-shift assay provides accurate and sensitive detection of typhoid fever within 15 minutes.
- The assay's compatibility with paper strip tests offers potential for low-cost, on-site clinical diagnostics, overcoming limitations of existing methods.
