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Updated: Oct 3, 2025
Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
Paper-based aptasensor for colorimetric detection of osteopontin
Ana Claudia Pereira1, Felismina T C Moreira2, Ligia R Rodrigues3
1CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal; MIT-Portugal Program, Lisbon, Portugal; BioMark@UC, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal.
A new cellulose-based aptasensor enables colorimetric detection of the cancer biomarker osteopontin (OPN) for point-of-care analysis. This sensitive and selective biosensor offers a promising tool for global cancer testing, meeting key REASSURED criteria.
Area of Science:
- Biomedical Engineering
- Biosensor Technology
- Cancer Biomarker Detection
Background:
- Osteopontin (OPN) is a significant cancer biomarker.
- Point-of-care (PoC) diagnostics require sensitive and accessible detection methods.
- Existing OPN detection methods may lack the speed and affordability for widespread PoC use.
Purpose of the Study:
- To develop a novel cellulose-based aptasensor for the colorimetric detection of osteopontin (OPN).
- To evaluate the sensitivity, selectivity, and accuracy of the aptasensor for OPN detection in various samples.
- To assess the aptasensor's suitability for point-of-care (PoC) applications based on the REASSURED criteria.
Main Methods:
- Chemically modifying cellulose paper to immobilize thiolated aptamers for OPN recognition.
- Utilizing Bradford reagent for colorimetric signal generation upon OPN binding.
- Employing smartphone imaging and ImageJ software for quantitative color analysis (RGB coordinates).
- Surface modification verification using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA).
Main Results:
- The aptasensor demonstrated high sensitivity with a wide linear range (R > 0.998) from 5-1000 ng/mL.
- A low detection limit (< 5 ng/mL) was achieved in both buffer and human serum solutions within 30 minutes.
- The biosensor exhibited excellent selectivity against interfering substances like bovine serum albumin and recombinant OPN.
- Analysis of spiked serum samples confirmed the method's accuracy.
Conclusions:
- The developed cellulose-based aptasensor provides a sensitive, selective, and accurate method for OPN detection.
- The colorimetric approach using smartphone imaging is suitable for point-of-care (PoC) analysis.
- The aptasensor aligns with the REASSURED criteria, indicating its potential for global cancer testing applications.
