Detection of Adrenaline Based on Substrate Recycling Amplification

Label-Free Detection of Epinephrine Using Flower-like Biomimetic CuS Antioxidant Nanozymes

A biosensor comprising crystalline CuS nanoparticles (NPs) was synthesized via a one-step simple coprecipitation route without involvement of a surfactant. The powder X-ray diffraction method has been used to evaluate the crystalline nature and different phases consist of the formation of CuS NPs. Mainly hexagonal unit cells consist of the formation of CuS NP unit cells. Most of the surfaces are covered with rhombohedral microparticles with a smooth exterior and surface clustering, examined by SEM images, and the shape of NPs was spherical, having an average size of 23 nm, as confirmed by TEM analysis. This study has focused on the peroxidase-mimicking activity, superoxide dismutase (SOD)-mimicking activity, and chemosensor-based colorimetric determination and detection of epinephrine (EP) neurotransmitters with excellent selectivity. The CuS NPs catalyzed the oxidation of the oxidase substrate 3, 3-5, 5 tetramethyl benzidine (TMB) with the help of supplementary H2O2 that followed Michaelis-Menten kinetics with excellent Km and Vmax values calculated by the Lineweaver-Burk plot. Taking advantage of the drop in absorbance upon introduction of EP for the CuS NPs-TMB/H2O2 system, a colorimetric route has been developed for selective and real-time detection of EP. The sensitivity of the new colorimetric probe was vibrant, having a linear range of 0-16 μM, and achieved a low limit of detection of 457 nM. Moreover, the present nanosystem exhibited appreciable SOD-mimicking activity which could effectively remove O2•- from commercial cigarette smoke, along with it acting as a potential radical scavenger as well. The new nanosystem effectively scavenged •OH, O2.-, and metal chelation which were investigated calorimetrically.

A cost effective strategy for dual channel optical sensing of adrenaline based on 'in situ' formation of copper nanoparticles

Assessment of adrenaline (ADR) levels in biological fluids and pharmaceutical formulations is of prime importance due to its association with many disease conditions. Here a novel, cost effective, dual channel sensing strategy is developed for ADR based on in situ formation of copper nanoparticles. The proposed sensor works via both fluorimetry and colorimetry. Visual detection was also enabled by color change of solution from pale blue to reddish brown. Here CuCl₂ solution is used as probe to simplify method and was function as excellent fluorimetric as well as colorimetric ADR sensor. Fabricated sensor is very simple, selective and reproducible in nature. Proposed sensor works fluorimetrically in linear range of 3.00 × 10^-5 to 5.00 × 10^-7 M and colorimetrically in linear range of 5.00 × 10^-4 to 2.00 × 10^-5 M. Artificial urine and commercial pharmaceutical formulations were successfully analyzed as samples for estimation of ADR by developed dual channel sensor.