51. Paper-based genetic assays with bioconjugated gold nanorods and an automated readout pipeline.
- Author
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Borri, Claudia, Centi, Sonia, Chioccioli, Sofia, Bogani, Patrizia, Micheletti, Filippo, Gai, Marco, Grandi, Paolo, Laschi, Serena, Tona, Francesco, Barucci, Andrea, Zoppetti, Nicola, Pini, Roberto, and Ratto, Fulvio
- Subjects
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SCIENTIFIC computing , *NANORODS , *QUANTUM dots , *GOLD nanoparticles , *BIOSENSORS , *MATERIALS science , *DETECTION limit - Abstract
Paper-based biosensors featuring immunoconjugated gold nanoparticles have gained extraordinary momentum in recent times as the platform of choice in key cases of field applications, including the so-called rapid antigen tests for SARS-CoV-2. Here, we propose a revision of this format, one that may leverage on the most recent advances in materials science and data processing. In particular, we target an amplifiable DNA rather than a protein analyte, and we replace gold nanospheres with anisotropic nanorods, which are intrinsically brighter by a factor of ~ 10, and multiplexable. By comparison with a gold-standard method for dot-blot readout with digoxigenin, we show that gold nanorods entail much faster and easier processing, at the cost of a higher limit of detection (from below 1 to 10 ppm in the case of plasmid DNA containing a target transgene, in our current setup). In addition, we test a complete workflow to acquire and process photographs of dot-blot membranes with custom-made hardware and regression tools, as a strategy to gain more analytical sensitivity and potential for quantification. A leave-one-out approach for training and validation with as few as 36 sample instances already improves the limit of detection reached by the naked eye by a factor around 2. Taken together, we conjecture that the synergistic combination of new materials and innovative tools for data processing may bring the analytical sensitivity of paper-based biosensors to approach the level of lab-grade molecular tests. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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