Detection of nicotine using surface enhanced Raman spectroscopy.

Abstract

It has been established that smoking is highly associated with the development of serious medical problems. Clinical research has become essential to study not only exposure to toxicants but also to establish new products’ regulations. Clinical study designs often require refrain from use of nicotine delivery product prior to the trial in order to homogenize nicotine levels in all participants and also to evaluate nicotine withdrawal symptoms. Typically, refrain from nicotine products is confirmed by the well-established breath carbon monoxide (CO) test. Nevertheless, CO test cannot detect the abstinence from using non-combustible tobacco products, such as Electronic Cigarettes (ECIG). There is a demand to develop a method to fulfil the clinical need to selectively assess nicotine intake. Previous methods for detection of nicotine included High Performance Liquid Chromatography (HPLC) and Gas chromatography (GC), but these are time consuming and costly. Recently, Surface Enhanced Raman spectroscopy (SERS) emerged as a potential technique providing a simple, rapid and low-cost method. In this study, SERS will be used as an alternative method to detect nicotine consumption. The ultimate aim of this project is to develop an analytical method able to detect low concentrations of nicotine in biological matrices, such as saliva or urine. To achieve that, a systematic study was conducted to develop surface enhancement consisting of nicotine adsorbed on stable nanoparticles. Initially, synthesis of silver nanoparticles was investigated, taking into consideration the reduction reagent, temperature, preparation time and stirring rate. Following, the enhancement of the nicotine detection was optimized by selecting the mixing techniques (Vortex Multi-Inlet Vortex Mixer (MIVM)) and the medium condition (mainly pH and salt concentration). The method was developed to quantify nicotine in urine samples, demonstrating an innovative way to detect nicotine in biological matrices at low concentrations.