A Brief Review of Recent Advances in Surface-Enhanced Raman Spectroscopy and Microfluidics Technology for the Ultrasensitive Detection of Pesticides

18 pags., 5 figs., 1 tab.The pesticide is any substance used to prohibit, destroy, or control pests, such as insects, fungus, rodents or, undesirable plant species that cause damage during crop production and storage. There are a lot of traditional methods to detect pesticides, among them gas chromatography (GC), high-performance liquid chromatography (HPLC), and their combinations with ultraviolet (UV) or mass spectroscopy. Nevertheless, these conventional techniques have several limitations, involving complicated pre-treatment steps, requiring expensive instruments, operational difficulty, lack of instrument portability, and difficulties in real-time monitoring. Surface-enhanced Raman spectroscopy (SERS) is one of the current leading techniques widely applied for the ultrasensitive detection of pesticides molecules. SERS takes advantage to combine the high specificity of Raman scattering with the signal amplification of electromagnetic enhancement provided by the excitation of surface Plasmon resonances in metallic nanostructures, together with the charge transfer mechanisms established between metal surfaces and analytes. In this brief review, types of classification of pesticides that can be classed have been reported. These classifications can provide valuable information on the chemistry of pesticides. The state of art of SERS, including a theoretical background study, is briefly described. Finally, some recent development and applications of optical and analytical techniques for pesticides detection have been summarized; a particular study will be focused on SERS combined with microfluidic technology that has appeared as advanced tools for surface enhanced Raman spectroscopy (SERS). They have been demonstrated to be interesting for in situ and real-time detection of analytes at extremely low concentrations.This work was carried out with financial support provided by the Spanish National Research Council in the frame of the project COOPB20373 of the iCOOP 2018 program of CSIC.Peer reviewe

Psychoactive substances use and associated factors among middle and high school students in the North Center of Morocco: a cross-sectional questionnaire survey

Abstract Background Data on psychoactive substance (PAS) consumption among adolescents in the North Center of Morocco are not at all available. Therefore, the current study aimed at investigating the prevalence and the determinants of psychoactive substances use among middle and high school students in this region. Methods A cross-sectional study was conducted from April 2012 to November 2013 in public middle and high schools in the North Central Region of Morocco. An anonymous self-administered questionnaire was used to assess psychoactive substances use among a representative sample of school students from the 7th to the 12th grade, aged 11–23 years, selected by stratified cluster random sampling. Factors associated with psychoactive substance use were identified using multivariate stepwise logistic regression analyses. Results A total of 3020 school students completed the questionnaires, 53.0 % of which were males. The overall lifetime smoking prevalence was 16.1 %. The lifetime, annual and past month rates of any psychoactive substance use among the study subjects were 9.3, 7.5, and 6.3 % respectively. Cannabis recorded the highest lifetime prevalence of 8.1 %, followed by alcohol 4.3 %, inhalants 1.7 %, psychotropic substances without medical prescription 1.0, cocaine 0.7, heroine 0.3, and amphetamine with only 0.2 %. Psychoactive substance use was associated with males more than females. The risk factors identified by multivariate stepwise logistic regression analyses were being male, studying in secondary school level, smoking tobacco, living with a family member who uses tobacco, and feeling insecure within the family. Conclusions The prevalence among all school students reported by the current study was comparable to the national prevalence. Efforts to initiate psychoactive substance prevention programs among school students should be made by designing such programs based on the significant factors associated with psychoactive substance use identified in this study

Additional file 1: of Suicidal behaviors among Moroccan school students: prevalence and association with socio-demographic characteristics and psychoactive substances use: a cross-sectional study

STROBE checklist for cross sectional studies. (DOC 88 kb

Additional file 1: of Psychoactive substances use and associated factors among middle and high school students in the North Center of Morocco: a cross-sectional questionnaire survey

English version of the questionnaire. (DOCX 27 kb