Raman enhancement effect of different silver nanoparticles on salbutamol

Authors: GUO, OINGHUI - Agricultural University Of China; PENG, YANKUN - Agricultural University Of China; Chao, Kuanglin - Kevin Chao

Submitted to: Heliyon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2022
Publication Date: 9/1/2022
Citation: Guo, O., Peng, Y., Chao, K. 2022. Raman enhancement effect of different silver nanoparticles on salbutamol. Heliyon. 8(6):e09576. https://doi.org/10.1016/j.heliyon.2022.e09576.
DOI: https://doi.org/10.1016/j.heliyon.2022.e09576

Interpretive Summary: Salbutamol is a ß-agonist drug commonly used to treat chronic disease such as asthma. Certain ß-agonists (e.g., ractopamine) are labeled for use in the U.S. as feed additives in food-producing animals to improve feed efficiency, increase growth rate, and increase muscle mass. FDA regulations prohibit extralabel use of medicated feeds. Salbutamol is not labeled by FDA for use as feed additives. Current veterinary drug residues detection methods are labor intensive, expensive, and highly technical making them difficult to use for real-time monitoring. At ARS we have developed macro-scale Raman imaging and spectroscopy technologies and methodologies for research addressing food integrity concerns arising from adulteration or contamination. In this study, Raman enhancement signal of salbutamol was compared between concentrated gold and silver colloids. Silver colloid had the best enhancement performance with detection limit of 0.2 mg/L on salbutamol. The adsorption effect of several silver colloids with different particle sizes on salbutamol was compared. Silver colloids with larger particle sizes were more conducive to the adsorption of salbutamol. The relationship between the concentration of salbutamol and the Raman intensity is linear. This benefits ARS by providing a rapid, inexpensive methodology to protect the public from specific prohibited substances entering the food supply for human consumption. This approach can assure prohibited levels of residues from feeds and from medicated feeds are absent in the diets of food animals.

Technical Abstract: Salbutamol is a ß-adrenergic receptor agonist compound which has been illicitly used as an animal growth promoter to improve carcass lean meat percentage. At present, the detection of salbutamol by SERS mostly uses gold colloid as substrate, which is expensive and has a high detection limit. In this report, Raman enhancement signal of salbutamol was compared with concentrated gold and silver colloids. The results show that the concentrated silver colloid prepared by reducing silver nitrate with hydroxylamine hydrochloride had superior performance. Three silver colloids with different particle sizes were synthesized by the same reducing agent and used as substrates for spectra acquisition of salbutamol to explore the enhancement performance of different silver nanoparticles sizes on salbutamol. The results showed that silver nanoparticles with larger particle sizes were more conducive to the adsorption of salbutamol. The relationship between the SERS intensity and salbutamol concentration is linear (R2 = 0.994). Validation set correlation coefficient was 0.988 and prediction root mean square error was 0.029 mg/L. This study can further the development of simple, low-cost, and more sensitive SERS detection methods based on silver colloid, instead of using gold colloid.