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Abstract The electrochemical detection of two pharmaceuticals, diclofenac (DCF) and carbamazepine (CBZ), was investigated as an oxidation current using boron‐doped nanocrystalline diamond (BDD) thin‐film electrodes. Both voltammetry and flow injection analysis with amperometric detection (FIA‐EC) were used to measure the drugs in standard solutions and a urine simulant. The oxidation potential for DCF wasca. 0.7 V vs. Ag/AgCl (3 M KCl) in 0.1 M phosphate buffer (pH 7.2) and wasca. 1.2 V for CBZ in 0.1 M perchloric acid. The DCF oxidation reaction was diffusion controlled at the detection potential with evidence of some surface fouling by reaction products. The CBZ oxidation reaction was also controlled by diffusion at the detection potential, but with no surface fouling. The voltammetric peak currents for both drugs increased linearly with the concentration in the micromolar range (r²≥0.994). FIA‐EC analysis of DCF and CBZ revealed a linear dynamic range from at least 0.1 to 100 μM with the actual minimum concentration detectable (S/N=3) being less than the lowest concentration measured. The recovery percentage for DCF in the urine simulant ranged from 94–108% and from 97–100% for CBZ, both assessed using square wave voltammetry. FIA‐EC data revealed that the BDD electrodes offer excellent intra and inter‐electrode repeatability with an RSD for DCF and CBZ of 4.90% and 3.81%, respectively. The BDD electrode provided good reproducibility and response stability over eight days of continuous use detecting both DCF and CBZ. Overall, BDD electrodes are a viable material  for the sensitive, selective, and reproducible electrochemical detection of these two pharmaceuticals. 

Independent research experiences in sustainable chemistryThe Research Experiences for Undergraduates (REU) programme in the Department of Chemistry at Michigan State University was created to inform students majoring in chemistry, biochemistry and chemical engineering about key societal sustainability challenges and to provide graduate-level independent research experiences that address aspects of these challenges. The REU programme exposes students to how sustainable practices are impacting research and technology development in chemistry and chemical engineering. The 10-week summer programme introduces students, many of whom are engaging in graduate-level research for the first time, to the multiple steps in the research process: (i) formulate research questions and a hypothesis, (ii) create a research design, (iii) execute an experimental plan, (iv) data analysis and interpretation, and (v) report out on the findings and their significance. 

The research experiences for undergraduates (REU) programGreg M. Swain, hailing from the Department of Chemistry at Michigan State University, examines cross-disciplinary training in sustainable chemistry and chemical processes, including the critical role of mentoring and finding research experiences for undergraduates. Sustainability is the practice of reducing the environmental impacts of human existence and conserving natural resources for future generations. Green chemistry is a part of the sustainability approach that encourages manufacturing processes and the design of products that minimize the use and generation of hazardous substances. Stated another way, sustainable chemistry and chemical processes should use resources, including energy and raw materials, “at a rate at which they can be replaced naturally, and the generation” of waste cannot be faster than the rate of their remediation, as Horváth IT points out. (1) 

We report femtosecond time-resolved measurements of the McLa!erty rearrangement following the strong-field tunnel ionization of 2-pentanone, 4-methyl-2-pentanone, and 4,4-dimethyl-2-pentanone. The pump−probe-dependent yields of the McLa!erty product ion are fit to a biexponential function with fast ("100 fs) and slow ("10 ps) time constants, the latter of which is faster for the latter two compounds. Following nearly instantaneous ionization, the fast time scale is associated with rotation of the molecule to a six-membered cyclic intermediate that facilitates transfer of the !-hydrogen, while the "50−100 times longer time scale is associated with a "-bond rearrangement and bond cleavage between the #- and $-carbons to produce the enol cation. These experimental measurements are supported by ab initio molecular dynamics trajectories, which further confirm the time scale of this important stepwise reaction in mass spectrometry. 

Cholinergic signaling, i.e., neurotransmission mediated by acetylcholine, is involved in a host of physiological processes, including learning and memory. Cholinergic dysfunction is commonly associated with neurodegenerative diseases, including Alzheimer’s disease. In the gut, acetylcholine acts as an excitatory neuromuscular signaler to mediate smooth muscle contraction, which facilitates peristaltic propulsion. Gastrointestinal dysfunction has also been associated with Alzheimer’s disease. This research focuses on the preparation of an electrochemical enzyme-based biosensor to monitor cholinergic signaling in the gut and its application for measuring electrically stimulated acetylcholine release in the mouse colon ex vivo. The biosensors were prepared by platinizing Pt microelectrodes through potential cycling in a potassium hexachloroplatinate (IV) solution to roughen the electrode surface and improve adhesion of the multienzyme film. These electrodes were then modified with a permselective poly(m-phenylenediamine) polymer film, which blocks electroactive interferents from reaching the underlying substrate while remaining permeable to small molecules like H2O2. A multienzyme film containing choline oxidase and acetylcholinesterase was then drop-cast on these modified electrodes. The sensor responds to acetylcholine and choline through the enzymatic production of H2O2, which is electrochemically oxidized to produce an increase in current with increasing acetylcholine or choline concentration. Important figures of merit include a sensitivity of 190 ± 10 mA mol−1 L cm−2, a limit of detection of 0.8 μmol L−1, and a batch reproducibility of 6.1% relative standard deviation at room temperature. These sensors were used to detect electrically stimulated acetylcholine release from mouse myenteric ganglia in the presence and absence of tetrodotoxin and neostigmine, an acetylcholinesterase inhibitor. 

Indium tin oxide (ITO) has been extensively used as a transparent conductor. The surface chemistry of ITO is amenable to reactions similar to those used to modify silica, but a long-standing issue has been understanding the density and robustness of the ITO surface-modification. We report on the formation of chemically bound Cd2+-complexed octadecylphosphonic acid (ODPA) monolayer formed on a Langmuir trough and deposited using Langmuir−Blodgett (LB) methodology onto an ITO surface, either in its native form or functionalized with phosphonate (RPO3^2−). The organization of the Langmuir monolayer depends on the pH and presence of Cd2+ in the aqueous subphase on which it is formed and on the functionalization of the ITO surface. We probe the permeability of the resulting LB−support interface electrochemically and the motional freedom characteristic of chromophores contained within the monolayer using fluorescence recovery after photobleaching (FRAP). Our data demonstrate that without modification of the ITO surface the monolayer is significantly permeable by the electrophores used (ferrocene and Ru3+), and surface modification to produce covalently bound phosphonate functionality results in a monolayer that is impermeable to the electrophores. FRAP studies reveal a relatively rigid monolayer aliphatic chain region for deposition on either native or modified ITO, suggesting direct Cd2+−ITO interactions. 

The article provides an overview of the motivations, goals, and structure of our REU Site: Cross-disciplinary Training in Sustainable Chemistry and Chemical Processes.