Platform For Detection Of H2O2 Research Articles

Hydroquinone colorimetric sensing based on platinum deposited on CdS nanorods as peroxidase mimics.

Pt deposited on CdS nanorods (Pt/CdS) have been prepared via the UV light photoreduction method. The Pt/CdS nanocomposites possess highly significantperoxidase-like activity with the assistance of the colorless substrate 3,3,5,5-tetramethylbenzidine (TMB). In the presence of peroxidase mimic Pt/CdS, TMB is quicklyoxidized into a typical blue product (oxTMB, which has an obvious absorption at 652nm) by H2O2 only in 3min, which is easily detected visually. The catalytic activity of Pt/CdS originates from the accelerated electron transfer between the reactants. Combining the peroxidase-like activity of Pt/CdS with the blue change of TMB, a fast colorimetric sensing platform for detection of H2O2 has been constructed with alinear range 0.10-1.00mMand a detection limit of 45.5μM. The platform developed isfurther used to detect hydroquinone (HQ) in the range1.0-10μM with a lower detection limit of 0.165μM. The colorimetric platform has a potential to detect HQ residue in real water samples with recoveries ranging from 83.56 to 91.76%. Graphical abstract.

Integrating Carbon Nanomaterials with Metals for Bio-sensing Applications

Age structure in most developed countries is changing fast as the average lifespan is increasing significantly, calling for solutions to provide improved treatments for age-related neurological diseases and disorders. In order to address these problems, a reliable way of recording information about neurotransmitters from in vitro and in vivo applications is needed to better understand neurological diseases and disorders as well as currently used treatments. Likewise, recent developments in medicine, especially with the opioid crisis, are demanding a swift move to personalized medicine to administer patient needs rather than population-wide averages. In order to enable the so-called personalized medicine, it is necessary to be able to do measurements in vivo and in real time. These actions require sensitive and selective detection of different analytes from very demanding environments. Current state-of-the-art materials are unable to provide sensitive and selective detection of neurotransmitters as well as the required time resolution needed for drug molecules at a reasonable cost. To meet these challenges, we have utilized different metals to grow carbon nanomaterials and applied them for sensing applications showing that there are clear differences in their electrochemical properties based on the selected catalyst metal. Additionally, we have combined atomistic simulations to support optimizing materials for experiments and to gain further understanding of the atomistic level reactions between different analytes and the sensor surface. With carbon nanostructures grown from Ni and Al + Co + Fe hybrid, we can detect dopamine, ascorbic acid, and uric acid simultaneously. On the other hand, nanostructures grown from platinum provide a feasible platform for detection of H2O2 making them suitable candidates for enzymatic biosensors for detection of glutamate, for example. Tetrahedral amorphous carbon electrodes have an ability to detect morphine, paracetamol, tramadol, and O-desmethyltramadol. With carbon nanomaterial-based sensors, it is possible to reach metal-like properties in sensing applications using only a fraction of the metal as seed for the material growth. We have also seen that by using nanodiamonds as growth catalyst for carbon nanofibers, it is not possible to detect dopamine and ascorbic acid simultaneously, although the morphology of the resulting nanofibers is similar to the ones grown using Ni. This further indicates the importance of the metal selection for specific applications. However, Ni as a continuous layer or as separate islands does not provide adequate performance. Thus, it appears that metal nanoparticles combined with fiber-like morphology are needed for optimized sensor performance for neurotransmitter detection. This opens up a new research approach of application-specific nanomaterials, where carefully selected metals are integrated with carbon nanomaterials to match the needs of the sensing application in question.

One-step preparation of core-shell Au@poly(m-phenylenediamine) without any extra reagent and electrocatalytic biosensing for H2O2

In this paper, a simple, one-step chemical synthesis of Au@poly(m-phenylenediamine) (PMPD) core-shell nanoparticles by direct dropping aqueous chloroauric acid aqueous solution to m-phenylenediamine aqueous solution was reported, which is a facile and green method. We further evaluate the use of the obtained Au@PMPD to modify glassy carbon electrode and for H2O2 electrocatalytic biosensing. The results indicate that the aggregated small Au nanoparticles in the inner part of PMPD could be an ideal sensing platform for H2O2 detection.