Electrodeposition of Silver Amalgam on Thin Gold Film Electrodes for Voltammetric Detection of 4Nitrophenol and DNA Labeled with Osmium TetroxideBipyridine Complex

Herein, electrodes made of vapordeposited thin gold films (vAuE) were used as an alternative substrate for the electrodeposition of silver amalgam particles (AgAPs), next to indium tin oxide and pyrolytic graphite, which are already used. The conditions and parameters of double pulse chronoamperometry were optimized for the mostsensitive voltammetric detection of 4nitrophenol (4NP). The resulting electrodes were characterized by scanning electron microscope with energy dispersive Xray spectroscopy

Lost gallstones during laparoscopic cholecystectomy as a common but underestimated complication—case report and review of the literature

IntroductionLaparoscopic cholecystectomy (LC) represents one of the most commonly performed routine abdominal surgeries. Nevertheless, besides bile duct injury, problems caused by lost gallstones represent a heavily underestimated and underreported possible late complication after LC.MethodsCase report of a Clavien-Dindo IVb complication after supposedly straightforward LC and review of all published case reports on complications from lost gallstones from 2000-2022.Case ReportAn 86-year-old patient developed a perihepatic abscess due to lost gallstones 6 months after LC. The patient had to undergo open surgery to successfully drain the abscess. Reactive pleural effusion needed additional drainage. Postoperative ICU stay was 13 days. The patient was finally discharged after 33 days on a geriatric remobilization ward and died 12 months later due to acute cardiac decompensation.ConclusionIntraabdominal abscess formation due to spilled gallstones may present years after LC as a late complication. Surgical management in order to completely evacuate the abscess and remove all spilled gallstones may be required, which could be associated with high morbidity and mortality, especially in elderly patients. Regarding the overt underreporting of gallstone spillage in case of postoperative gallstone-related complications, focus need be put on precise reporting of even apparently innocuous complications during LC

Biophysical and electrochemical studies of protein-nucleic acid interactions

This review is devoted to biophysical and electrochemical methods used for studying protein-nucleic acid (NA) interactions. The importance of NA structure and protein-NA recognition for essential cellular processes, such as replication or transcription, is discussed to provide background for description of a range of biophysical chemistry methods that are applied to study a wide scope of protein-DNA and protein-RNA complexes. These techniques employ different detection principles with specific advantages and limitations and are often combined as mutually complementary approaches to provide a complete description of the interactions. Electrochemical methods have proven to be of great utility in such studies because they provide sensitive measurements and can be combined with other approaches that facilitate the protein-NA interactions. Recent applications of electrochemical methods in studies of protein-NA interactions are discussed in detail

Electrodeposition of silver amalgam particles on ITO – Towards novel electrode material

© 2017 Elsevier B.V. Silver solid amalgam represents up to now the most suitable alternative electrode material to metallic mercury in electroanalytical chemistry. Controlled electrodeposition of variable (sub)micrometer-sized silver amalgam particles (AgAP) on the surface of transparent indium-tin oxide (ITO) electrode from an electrolyte containing Ag+ and Hg2+ ions is reported here, as a novel perspective method suitable for preparation of nano-structured silver amalgam electrode material. Elemental analysis of the composition and morphology of the AgAP decorating the ITO was studied by scanning electron microscopy including energy-disperse X-ray spectroscopy and by image processing software. Particle composition, size, and surface coverage are controllable by selection of the Ag+/Hg2+ ratio in the electrodeposition solution and by setting of individual parameters of applied double pulsed/potential chronoamperometry. Applicable potential window of thus prepared ITO-AgAP electrode was found to be within +0.2 to −1.0 V in 0.2 acetate buffer pH 5.0. Utilized voltammetric and chronoamperometric methods revealed significant enhancement in electrochemical reducibility of selected model organic nitro-compound (shift of the peak potential about 300 mV to more positive potentials). Its further employment in UV/Vis spectroelectrochemical cell provided information about number of consumed electrons and kinetic characteristics. Furthermore preferential adsorption of calf thymus DNA at AgAP than ITO was observed by fluorescence microscopy indicating its potential applicability in (bio-)spectroelectrochemical methods. Further advantages and potential applications are also proposed and discussed

Lightweight ITO electrodes decorated with gold nanostructures for electrochemical applications

Gold nanostructures were fabricated on a transparent indium tin oxide (ITO) coated PET substrate by an electrodeposition technique from a potassium gold (III) chloride solution for two different types of applications. It was found that the optical transparency of lightweight ITO electrodes could be maintained by depositing isolated gold nanostructures while opening up the use of these electrodes for inner sphere electron reactions, such as hydroquinone oxidation, which are not possible at ITO electrodes. For practical applications the adhesion of gold to the ITO electrode was improved by modifying the ITO surface with 3-mercaptopropyl-trimethoxysilane (MPS). Compared to Au/ITO, the Au/MPS/ITO electrode showed vastly improved electrochemical activity toward various electron transfer reactions when subjected to mechanical stress. The biosensing properties of the Au/MPS/ITO electrode was also investigated by studying the detection of immobilized DNA on the Au/MPS/ITO electrode via electrochemical impedance spectroscopy (EIS).</p