Supplementary data for article: Mehmeti, E.; Stanković, D. M.; Chaiyo, S.; Zavasnik, J.; Žagar, K.; Kalcher, K. Wiring of Glucose Oxidase with Graphene Nanoribbons: An Electrochemical Third Generation Glucose Biosensor. Microchimica Acta 2017, 184 (4), 1127–1134. https://doi.org/10.1007/s00604-017-2115-5

Supplementary material for: [https://doi.org/10.1007/s00604-017-2115-5]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2438

Manganese dioxide-modified carbon paste electrode for voltammetric determination of riboflavin

A carbon paste electrode bulk was modified with MnO2 and investigated for use as an electrochemical sensor for riboflavin (vitamin B-2) using differential pulse voltammetry (DPV). Riboflavin displays a well expressed oxidation peak at -0.15 V (versus Ag/AgCl) in solutions with a pH value of 2. Effects of pH value, pulse amplitude and pulse time were optimized by employing DPV. The signals obtained are linearly related to the concentrations of riboflavin in the range from 0.02 to 9 mu M. Other features include a 15 nM detection limit, and good reproducibility (+/- 3 %) and repeatability (+/- 2 %). Interferences by common compounds were tested, and the method was successfully applied to the determination of riboflavin in pharmaceutical formulations where is gave recoveries in the range from 95 to 97 %

Supplementary data for article: Mehmeti, E.; Stanković, D. M.; Chaiyo, S.; Zavasnik, J.; Žagar, K.; Kalcher, K. Wiring of Glucose Oxidase with Graphene Nanoribbons: An Electrochemical Third Generation Glucose Biosensor. Microchimica Acta 2017, 184 (4), 1127–1134. https://doi.org/10.1007/s00604-017-2115-5

Supplementary material for: [https://doi.org/10.1007/s00604-017-2115-5]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2438

Industrial Buyer Innovation Adoption Model: A Focus on a Smartphone-Based Electrochemical Analytical Device for Toxic Heavy Metal Detection

Smartphone-Based Electrochemical Analytical Devices (SEAD) enable sophisticated toxic heavy metal quantification experiments to be conducted anywhere with high precision, selectivity, and sensitivity. However, a very limited number of such technologies are able to make the transition from the lab to the competitive B2B marketplace. The purpose of this paper is to examine the factors influencing SEAD adoption in the manufacturing industry using the Industrial Buyer Innovation Adoption (IBIA) model, which integrates B2B consumer behavior theories and technology acceptance models from the past 50 years. Analysis of data collected from 400 corporations in Thailand revealed that sellers, buyers, internal organization and invented technology advantage variables predicted industrial innovation adoption based on binary logistic regression. This research contributes to the understanding of SEAD transition from scientific knowledge to sustainable technology and diffusible innovation. The ambitious IBIA framework is potentially an alternative managerial tool for holistically assessing and creating adoptable innovative business models for new technologies

Wiring of glucose oxidase with graphene nanoribbons: an electrochemical third generation glucose biosensor

A reagentless third generation electrochemical glucose biosensor was fabricated based on wiring the template enzyme glucose oxidase (GOx) with graphene nanoribbons (GN) in order to create direct electron transfer between the co-factor (flavin adenine dinucleotide, FAD) and the electrode. The strategy involved: (i) isolation of the apo-enzyme by separating it from its co-enzyme; (ii) preparation of graphene nanoribbons (GN) by oxidative unzipping of multi-walled carbon nanotubes; (iii) adsorptive immobilization of GNs on the surface of a screen printed carbon electrode (SPCE); (iv) covalent attachment of FAD to the nanoribbons; (v) recombination of the apo-enzyme with the covalently bound FAD to the holoenzyme; and (vi) stabilization of the bio-layer with a thin membrane of Nafion. The biosensor (referred to as GN/FAD/apo-GOx/Nafion/SPCE) is operated at a potential of +0.475 V vs Ag/AgCl/{3 M KCl} in flow-injection mode with an oxygen-free phosphate buffer (pH 7.5) acting as a carrier. The signals are linearly proportional to the concentration of glucose in the range from 50 to 2000 mgai...L-1 with a detection limit of 20 mgai...L-1. The repeatability (10 measurements, at 1000 mgai...L-1 glucose) is +/- 1.4% and the reproducibility (5 sensors, 1000 mgai...L-1 glucose) is +/- 1.8%. The biosensor was applied to the determination of glucose in human serum.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3104

Electrochemical determination of ajmalicine using glassy carbon electrode modified with gold nanoparticles

A simple, sensitive, and economically viable electrochemical method for the determination of ajmalicine was developed. The procedure involves a glassy carbon electrode modified with gold nanoparticles (GCE/AuNPs). In the work presented here gold nanoparticles were attached to the glassy carbon electrode by adsorption. Cyclic voltammetry was used for the first time for the electrochemical characterization of ajmalicine and differential pulse voltammetry for its quantitative determination. Britton-Robinson buffer solution in a range of pH values served as supporting electrolyte. The experimental conditions were optimized and it was found that ajmalicine provided a well-defined oxidation peak at a potential of +0.8 V vs. Ag/AgCl (3 M KCl). The method for the determination of ajmalicine showed a dynamic range for concentrations from 5 to 50 A mu M with a detection limit of 1.7 A mu M, good repeatability (RSD of 1.4 %) and reproducibility (RSD of 2.5 %). The effect of possible interferents (yohimbine, reserpine) appeared to be negligible. The proposed procedure was successfully applied for the first time to the determination of ajmalicine in commercially available oral solutions for medical applications with results in good agreement with the declared content of ajmalicine. [GRAPHICS

Integrated lateral flow immunoassays using trimethylsilyl cellulose barriers for the enhanced sensitivity of COVID-19 diagnosis

Lateral flow immunoassays (LFIAs) serve as rapid and convenient tools for disease screening. However, there is room for enhancing diagnostic sensitivity. Therefore, this paper introduces a novel material combined with lateral flow immunoassays to improve the sensitivity of COVID-19 detection and diagnosis. Trimethylsilyl cellulose (TMSC) was printed on the device between the test and control line to delay the flow of the solution, which resulted in a more excellent binding of the immunoassay. These delay-LFIAs (d-LFIAs) were developed for the diagnosis of COVID-19, targeting the detection of immunoglobulins G and M, as well as the COVID-19 antigen. Under optimized conditions, the d-LFIA increased the sensitivity by up to 5 times compared to that of conventional LFIAs. Moreover, it exhibited the ability to detect IgG, IgM, and SARS-CoV-2 antigens as low as 1 ng/mL (limit of detection) by the naked eye. In addition, the application of this device to real samples yielded highly consistent results with those obtained from other LFIAs and standard SARS-CoV-2 diagnostic methods (such as enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction) diagnosis. Therefore, we expect this device to be a new platform for highly sensitive, easy, and affordable immunoassay strip testing to certify future emerging diseases