Development of an Electrochemical Sensor for the Detection of Mephedrone on a Modified Carbon Paste Electrode with Polymerized Silver Nanoparticles Capped with Saffron_
* _G. C. Papaioannou, S. Karastogianni
* and S. Girousi_
* Analytical Chemistry Laboratory, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
* Correspondence: skarastogianni@hotmail.com (S.K. ), girousi@chem.auth.gr (S.G.)  
Electrochemical deposition methods provide a simple, repeatable, and green method for the formation of thin and uniform polymer film on the electrode surface [1]. Mephedrone or 4-methylmethachtinone is becoming the most popular new psychoactive substance among youth as a recreational drug [2]. Mephedrone (1-(4-methylphenyl)-2-methylaminopr opane-1-one) is one of the most potent derivatives of the cathinone. Mephedrone increase the level of lipid peroxidation and expression of antioxidant enzymes [3]. Regarding mephedrone's detection, only few attempts were made using electrochemical sensors, such as the imprinted electrochemical sensor, based on sol-gel molecular imprinted polymer polytytramine and gold nanoparticles (f-MWCNT@AuNPs) [4]. Therefore, this study describes the development of a novel, sensitive, selective, environmentally friendly, and cost-effective electrochemical sensor for the detection of mephedrone. Silver nanoparticles (AgNPs) were capped with saffron (AgNPs@Sa) using a green method [5] and studied with ultraviolet-visible spectroscopy (UV-Vis), as well as with infrared spectroscopy (IR). The morphology of AgNPs@Sa was studied with electron scanning microscopy (SEM). The cyclic voltammetric deposition of poly-AgNPs@Sa on a carbon paste electrode (CPE) was performed by cycling the potential for five scans in phosphate buffer pH 7.0 containing silver nanoparticles. The electrode was immersed in a solution that contains the mephedrone. The sensor was evaluated under optimum condition to evaluate its analytical features such as linearity, selectivity, stability, and reproducibility. Moreover, it was applied for the analysis of mephedrone in real samples. To the best of our knowledge, it is the first detection effort to electrochemically analyze mephedrone with AgNPs as electrode surface modifiers. Figure 42: PLA-PEAd 60–40 day 0 (**left**) and day 18 (**right**). ## References  
* (1) Kan, X.; Zhou, H.; Li, C.; Zhu, A.; Xing, Z.; Zhao, Z. Imprinted electrochemical sensor for dopamine recognition and determination based on a carbon nanotube/polypyrrole film. _Electrochim. Acta_**2012**, _63_, 69-75. * (2) Palazzoli, F.; Santunione, A.L. ; Verri, P.; Vandelli, D.; Silingardi, E. Post-mortem distribution of mebedrone and its metabolites in body fluids and organ tissues of an intoxication case. _J. Pharm. Biomed. Anal._**2021**, _201_, 114093. * (3) Buzhdygan, T.P. ; Rodrigues, C.R. ; McGary, H.M.; Khan, J.A. ; Andrews, A.M.; Rawls, S.M. ; Ramirez, S.H. The psychoactive drug of abuse mebedrone differentially disrupts bloodbrain barrier prop. _J. Neuroinflammatory_. **2021**, _63_, 1-15. * (4) Razavipanah, I.; Alipour, E.; Deiminiat, B.; Rounaghi, G.H. A novel electrochemical imprinted sensor for ultrasensitive detection of the new psychoactive substance \"Mephedrone\". _Biosens. Bioelectron._**2018**, _119_, 163-169. * (5) Karastogianni, S.; Girousi, S. A novel electrochemical bioimprinted sensor of butyl paraben on a modified carbon paste electrode with safranine-o capped to silver nanoparticles. _Int. J. Cur. Res._**2017**, \(9\), 61118-61124. * (6)_18.6. Electrochemical Sensing of Maple Syrup Urine Disease (MSUID) Biomarkers in a Modified Carbon Paste Electrode Saffron Coupled with Silver Nanoparticles_
* (7)**S. Karastogianni \({}^{*}\) and S. Girousi**Analytical Chemistry Laboratory, Chemistry Department, Aristotle University of Thessaloniki, 54248 Thessaloniki, Greece
* \({}^{*}\) Correspondence: skarastogianni@hotmail.com  
Branched-chain amino acids (b AAs) (leucine (Leu), isoleucine (Ile), and valine (Val)) partake in proteinic synthesis and protein catabolism [1].