Electrochemical luminescence sensor based on CDs@HKUST-1 composite for detection of catechol

A novel electrochemiluminescent sensor based on AgMOF@N-CD composites for sensitive detection of trilobatin

In this study, a novel electrochemiluminescent (ECL) sensor for highly sensitive detection of trilobatin (Tri) was developed based on silver metal-organic frameworks (AgMOFs) and nitrogen-doped carbon quantum dots (N-CDs). N-CDs exhibited high ECL intensity but poor ECL stability, while AgMOFs had a large specific surface area, high porosity, and good adsorption properties. Compositing both of them not only improved the ECL stability of N-CDs, but also enhanced the ECL strength of materials, so AgMOF@N-CD composites were used as the luminophore of the sensor. Under the optimized conditions, the ECL sensor showed a linear range of 1.0 × 10-7 M to 1.0 × 10-3 M for the detection of Tri, and the detection limit was as low as 5.99 × 10-8 M (S/N = 3). In addition, the sensor had excellent reproducibility, stability, and anti-interference ability. It could be utilized for the detection of Tri in real samples with recoveries of 95.78-102.26%, indicating that the constructed ECL sensor for detecting Tri possessed better application prospects.

Antenna effect of perylene-sensitized up-conversion luminescent material amplifies the signal of electrochemiluminescence biosensor platform for the ultra-sensitive detection of enrofloxacin

Recently, up-conversion luminescent (UCL) materials have caught extensive sight on account of their excellent biocompatibility and weak automatic fluorescence background, but the low optical signal makes researchers shy away. Organic dye-sensitized UCL materials can improve the low optical signal drawback of UCL and rejuvenate it with adjustable optical properties and unique antenna effects. In this work, an efficient, simple and selective electrochemiluminescence (ECL) sensing platform was developed for determination of enrofloxacin (ENR). 3,4,9,10-perylene tetracarboxylic acid (PTCA) was successfully used as an "antenna" to improve the ECL performance of the UCL nanoparticles (PEI-NaYF4: Yb, Er) due to its appropriate excitation spectrum position and superior electron transfer rate. The specific recognition function of the aptamer enabled the sensor to eliminate the interference from conspecific impurity. In the presence of ENR, the specific combination of ENR with aptamer made the aptamer fall from surface of the electrode, thus we could see a considerable enhancement of signal. Under the most favourable conditions, the aptasensor based on antenna effect displayed a wide detection range (1.0 × 10-14∼1.0 × 10-6 M), low limit of detection (LOD = 3.0 × 10-15 M) and receivable recoveries (96.0%-102.4%) during water samples analysis. At this point, antenna effect provides a powerful strategy to expand the application of UCL in the field of ECL biosensing.

Highly Selective and Sensitive Voltammetric Method for the Detection of Catechol in Tea and Water Samples Using Poly(gibberellic acid)-Modified Carbon Paste Electrode

Despite the wide range of applications of catechol (CC) in agrochemical, petrochemical, textile, cosmetics, and pharmaceutical industries, its exposure to the environment leads to health issues as it is carcinogenic. This increased the concern over the risk of exposure level of CC in the environment, and monitoring its level has become critical. In this work, we report the fabrication of poly-gibberellic acid-modified carbon paste electrode (PGBAMCPE) to be a simple, viable, and effective electrochemical electrode for the determination of CC. This was synthesized by a simple electropolymerization method by the cyclic voltammetry (CV) technique. The electrodes were characterized by field emission electron microscopy, energy-dispersive X-ray spectroscopy, and electrochemical impedance spectroscopy. Compared to the bare carbon paste electrode, the sensitivity for CC fortified at PGBAMCPE in both CV and differential pulse voltammetry (DPV). We succeeded attaining a lower detection limit of 0.57 μM by the DPV method. The developed electrode was observed to be highly conductive, transducing, stable, and reproducible and was highly selective with anti-interfering properties from the determination of CC with hydroquinone simultaneously. The applicability of the electrode was confirmed from the detection CC in tea and water samples with good recoveries. This substantiates that PGBAMCPE is promising and consistent for the rapid monitoring of CC-contaminated area and clinical diagnosis.

Facile synthesis of nitrogen-doped graphene quantum dots as nanocarbon emitters for sensitive detection of catechol

Development of nanomaterial-based electrochemiluminescence (ECL) emitters is highly desirable for the fabrication and wide applications of ECL sensors. Herein, nitrogen-doped graphene quantum dots (NGQDs) were easily synthesized as nanocarbon emitters with anodic ECL for sensitive ECL determination of catechol (CC). Facile synthesis of NGQDs was easily achieved using molecular fusion of a carbon precursor in a one-step hydrothermal process. The synthesis has advantages of simple and convenient operation and high yield. The as-prepared NGQDs have uniform size, good crystallinity, single-layered graphene structure, and excitation-independent fluorescence. In the presence of hydrogen peroxide (H₂O₂), NGQDs exhibit high anodic ECL owing to the presence of functional hydrazide groups. As CC could significantly reduce the ECL intensity of NGQDs, sensitive determination of CC was realized with a linear range from 100 nM to 10 μM and 10 μM to 60 μM with a low limit of detection (LOD, 42 nM). The determination of CC in environmental water was also achieved with high reliability.

Nitrogen-doped graphene quantum dots are easily synthesized and can be used as nanocarbon emitters for sensitive electrochemiluminescence detection of catechol.