Delivering Inorganic and Organic Reagents and Enzymes from Zein and Developing Optical Sensors.
Nowadays, interest in using environmentally friendly materials is increasing in many fields. However, the rational design of sensors with biodegradable materials is a challenge. The main aim of this work is to show the possibility of using zein, a protein from corn, as a biodegradable and low-cost material for immobilizing, stabilizing, and delivering different kind of reagents for developing optical sensors. Enzymes, metallic salts, and aromatic and small organic compounds were tested. In addition, different techniques of immobilization, entrapment and adsorption, were used, and different formats, such as solid devices and also multiwell platforms, were proposed. The capacity of zein for i…
New Reusable Solid Biosensor with Covalent Immobilization of the Horseradish Peroxidase Enzyme: In Situ Liberation Studies of Hydrogen Peroxide by Portable Chemiluminescent Determination.
Herein, we reported a chemiluminescent biosensor based on the covalent immobilization of the horseradish peroxidase (HRP) enzyme on a polydimethylsiloxane (PDMS) support to quantify in situ hydrogen peroxide (H2O2). The chemiluminescent reaction based on the use of luminol as an oxidizable substrate, with HRP as the catalyst, has been used in order to quantify H2O2 as the oxidizing agent. The performance of the proposed biosensor has been demonstrated to determine H2O2 liberated by cells in a culture medium and for evaluating the delivery of H2O2 from denture cleaner tablets, as examples of application. For both analyses, the results indicated that the biosensor is cost-effective, sensitive…
Monofunctional pyrenes at carbon nanotube electrodes for direct electron transfer H2O2 reduction with HRP and HRP-bacterial nanocellulose
Abstract The non-covalent modification of carbon nanotube electrodes with pyrene derivatives is a versatile approach to enhance the electrical wiring of enzymes for biosensors and biofuel cells. We report here a comparative study of five pyrene derivatives adsorbed at multi-walled carbon nanotube electrodes to shed light on their ability to promote direct electron transfer with horseradish peroxidase (HRP) for H2O2 reduction. In all cases, pyrene-modified electrodes enhanced catalytic reduction compared to the unmodified electrodes. The pyrene N-hydroxysuccinimide (NHS) ester derivative provided access to the highest catalytic current of 1.4 mA cm−2 at 6 mmol L−1 H2O2, high onset potential …
In Situ Analysis Devices for Estimating the Environmental Footprint in Beverages Industry
Abstract The need to calculate the environmental footprint could mean the integration of sustainability in differentiation strategies for beverages industries. The parameters for estimating the footprint are outlined and discussed. The main negative impacts are related to water pollution, atmospheric pollution, and solid waste. Agro-industrial effluents may contain pesticides, complex oils, alkaline or acidic compounds, and other organic substances. As for atmospheric emissions, particulate material, SO2, NOx, hydrocarbons, and other organic compounds, can be mentioned. The state of art of in situ analysis devices for this purpose is described. The devices are compared through the tool CALI…