New Biosensors Decorated with Silver Nanoparticles Enable Sensitive Detection of Acyclovir Drug on Filter Paper Substrates

Recently, the emergence of antiviral drugs to treat sexually transmitted diseases (STDs), such as hepatitis B and herpes simplex, has taken on greater importance as more patients become afflicted with these conditions. One of these antiviral drugs, acyclovir (ACV), is commonly used in clinical settings (1). When administered appropriately and in small doses, ACV is effective at treating diseases like hepatitis B, herpes simplex, and varicella zoster. However, high doses of ACV can result in kidney toxicity, and therefore do more harm than good (1). A recent study conducted by researchers at Yasuj University of Medical Sciences in Iran was designed to develop a solution that can accurately detect this drug in various applications (1). The research team developed a biosensor platform using surface-enhanced Raman spectroscopy (SERS) combined with filter paper substrates containing silver nanoparticles (AgNPs), which was successful in detecting ACV on filter paper substrates (1).

antiviral drugs, anti-viral drug against COVID-19 virus or coronavirus, | Image Credit: © Ahmet Aglamaz - stock.adobe.com

The study employed a chemical reduction procedure to synthesize AgNPs, which were characterized using various techniques such as ultraviolet-visible (UV-vis) spectroscopy, field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and atomic force microscopy (AFM) (1). The, the AgNPs were coated onto filter paper substrates, creating SERS-active filter paper substrates (SERS-FPS) that can detect ACV's molecular vibrations (1). The stability of the substrates was evaluated using ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) analysis (1). The researchers found that the SERS-FPS had a limit of detection (LOD) of 10^-12 M and exhibited good reproducibility and sensitivity, with a mean relative standard deviation (RSD) of 4.19% for ten repeated tests (1).

The biosensors exhibited an impressive enhancement factor, reaching 3.024 × 10⁵ and 3.058 × 10⁵ experimentally and through simulation, respectively (1). The Raman results demonstrated the promising performance of the SERS-FPS for detecting ACV, showcasing its potential for SERS-based investigations (1). Most importantly, the fabricated biosensors displayed chemical stability, reproducibility, and disposability, which are all attributes needed for the biosensor to be effective in detecting trace substances (1).

As a result, a reliable and sensitive method for detecting ACV on filter paper substrates was realized. This discovery can lead to this approach being utilized more frequently in environmental monitoring, pharmaceutical research, and clinical diagnostics. The combination of SERS and filter paper substrates decorated with AgNPs offers a simple, cost-effective, and portable platform for rapid and on-site analysis (1). The researchers envision that this biosensor technology holds great potential for detecting other trace substances, contributing to advancements in the field of biosensing and healthcare (1).

Reference

(1) Eskandari, V.; Sahbafar, H.; Karooby, E.; Heris, M. H.; Mehmandoust, S.; Razmjoue, D.; Hadi, A. Surface-Enhanced Raman scattering (SERS) filter paper substrates decorated with silver nanoparticles for the detection of molecular vibrations of Acyclovir drug. Spectrochimica Acta Part A: Mol. Biomol. Spectrosc. 2023, 298, 122762. DOI: 10.1016/j.saa.2023.122762