查找使用阿拉丁产品的科研文献

Promoting effect of WS2 quantum dots on cathodic lucigenin ECL and its sensing application in Pb2+ detection

Jing Wang,Fuge Chai,Mengya Fan,Yongping Dong

The present work focuses on developing a highly sensitive ECL sensor for Pb 2+ detection based on WS 2 quantum dots (QDs). A top-down sonication-assisted liquid-phase exfoliation method was employed to synthesize WS 2 QDs which were characterized by TEM, XPS, Raman spectroscopy and electrochemistry. It was found that WS 2 QDs could not only generate mild cathodic ECL itself but also significantly promote the cathodic ECL of lucigenin. The electrochemical results suggested that WS 2 QDs could effectively accelerate the reduction process of dissolved oxygen and lucigenin, thereby greatly amplifying the ECL intensity. The specific interaction between Pb 2+ and WS 2 QDs could significantly decrease ECL signal due to the depletion of WS 2 QDs, based on which an ECL sensor for detecting Pb 2+ was developed. Under the optimal condition, a good linear relationship between the inhibited ECL signal and the logarithm of Pb 2+ concentration was obtained in the range from 1 nM to 50 μM, with a low detection limit of 10.4 pM. Moreover, the fabricated sensor exhibited high sensitivity and excellent selectivity, and could be used for the sensitive detection of Pb 2+ in real samples.

Much Stronger Chemiluminescence of 9-Mesityl-10-methylacridinium Ion than Lucigenin at Neutral Conditions for Co2+ Detection

Hongzhan Liu,Fangshuo Liu,Kaixiang Ji,Yuriy T. Zholudov,Islam M. Mostafa,Baohua Lou,Wei Zhang,Guobao Xu

9-Mesityl-10-methylacridinium ion (Acr+-Mes) is a donor–acceptor molecule with a much longer lifetime and a higher energy electron transfer excited state than natural photosynthetic reaction centers. Unlike lucigenin with a coplanar geometry, Acr+-Mes has an orthogonal geometry. There is no π conjugation between Acr+ and Mes. Due to its special electron donor–acceptor structure, it does not rely on strong alkalinity to generate an electron transfer state like lucigenin, which makes it possible to achieve chemiluminescence (CL) under weakly alkaline or neutral conditions. In this study, we report Acr+-Mes CL for the first time. Acr+-Mes generates about 400 times stronger CL intensity than lucigenin under neutral conditions (pH = 7) using KHSO5 as the coreactant. Moreover, Co2+ can enhance Acr+-Mes/KHSO5 CL remarkably. Acr+-Mes/KHSO5 CL enables Co2+ detection with a linear range of 0.5–500 nM and a limit of detection of 28 pM (S/N = 3). This method was tested for the detection of Co2+ in lake water, and the standard recovery rate of 96.8–107% was achieved. This study provides a new way to develop efficient CL systems in neutral solutions.

A highly sensitive fluorescence sensor based on lucigenin/chitosan/SiO2 composite nanoparticles for microRNA detection using magnetic separation

Zheng Chang,Jing Feng,Xingwang Zheng

In this paper, a convenient reverse-phase microemulsion method for the synthesis of SiO 2 nanoparticles (NPs) by simply introducing the chitosan and fluorescent dye of lucigenin during the formation reaction of SiO 2 NPs was proposed. Addition of chitosan can make the SiO 2 NPs porous, and increases lucigenin molecule incorporation into chitosan/SiO 2 NPs nanopores based on electrostatic interaction and supermolecular forces. Therefore, fluorescence quantum yield of the lucigenin/chitosan/SiO 2 composite nanoparticles was increased by introduction of chitosan and compared with lucigenin/SiO 2 NPs without chitosan. Because the number of negative charges carried when using single-stranded DNA (ssDNA) was different from that of double-stranded DNA (dsDNA), the numbers of lucigenin/chitosan/SiO 2 composite nanoparticles with positive charge adsorbed using ssDNA or dsDNA were different. Consequently, fluorescence intensity caused using ssDNA or dsDNA/miRNA was clearly discriminative. With increase in target DNA/miRNA concentration, the difference in fluorescence intensity also increased, resulting in a good linear relationship between fluorescence intensity sensitizing value and target miRNA concentrations. Therefore, a new fluorescence analysis method for direct detection of let-7a in human gastric cancer cell samples without enzyme, label free and no immobilization was established using lucigenin/chitosan/SiO 2 composite nanoparticles as a DNA hybrid indicator. The proposed method had high sensitivity and selectivity, low cost and the detection limit was 10 fM (S/ N = 3).

Lucigenin-Tris(2-carboxyethyl)phosphine Chemiluminescence for Selective and Sensitive Detection of TCEP, Superoxide Dismutase, Mercury(II), and Dopamine

Muhammad Saqib,Shahida Bashir,Haijuan Li,ShanShan Wang,Yongdong Jin

Development of simple and effective chemiluminescence (CL) systems for multiple sensing applications is significantly important but still a challenge. Until now, the majority of CL systems primarily utilized hydrogen peroxide (H2O2) as coreactant, which is limited in its stability and selectivity due to the easy decomposition of H2O2 in the presence of several ions. In this study, we develop a new and intense CL system by combined use of tris(2-carboxyethyl)phosphine (TCEP), a highly solution stable and pH-tolerant tertiary phosphine, with lucigenin for the first time. The effective pairing leads to a significant ∼23 times CL enhancement over classic the lucigenin–H2O2 system without employing additional catalysts. By virtue of this fascinating platform, a sensitive CL method has been developed for the multiple detection of TCEP (LOD = 70 nM), lucigenin (LOD = 4.0 nM), superoxide dismutase (LOD = 0.8 ng/mL), Hg2+(LOD = 0.3 nM), and dopamine (LOD = 3.0 nM), with a linear range of 0.1–320 μM, 0.01–55 μM, 0.005–0.5 μg/mL, 1.0–600 nM, and 0.01–0.8 μM, respectively. Remarkably, this CL method exhibited superior selectivity over several potential interferents. Moreover, the proposed method achieved excellent recoveries in the range of 94.0–102.3% for both Hg2+ detection in lake water and dopamine detection in human serum real samples. We envision that broad applications of TCEP may lead to construct new CL systems, pushing forward for efficient detection of various analytes.

Sericin as a New Coreactant for Lucigenin Chemiluminescence: A Novel System for the Ultrasensitive Detection of Sericin and Superoxide Dismutase

Muhammad Saqib,Wen-Xin Chen,Yun Lei,Ai-Lin Liu

Chemiluminescence (CL) assays are often constrained by the limited availability of coreactants that combine strong signal amplification with biocompatibility. Herein, we report for the first time that sericin, a natural protein derived from silk, serves as a highly efficient coreactant in the lucigenin CL system under alkaline conditions. Impressively, this new lucigenin–sericin CL system generates an unprecedented ∼43-fold higher emission intensity compared to the traditional lucigenin–hydrogen peroxide system. Moreover, the mechanistic studies reveal that sericin, with its electron-rich functional groups, significantly promotes the generation of superoxide radicals (O2•–). This, in turn, accelerates the lucigenin oxidation pathway, leading to significant enhancement in CL signal. Leveraging this enhanced system, we developed a dual-function CL platform for the ultrasensitive detection of sericin (limit of detection, LOD = 0.12 μM) and superoxide dismutase (SOD, LOD = 0.28 ng/mL), exhibiting an extended linear range spanning from 0.25 to 50 μM and 0.5 to 60 ng/mL, respectively, the latter based on CL quenching phenomena. This method offers compelling superiority in terms of simplicity, rapid analysis, enhanced sensitivity, higher selectivity, and cost-effectiveness. Moreover, this method successfully achieved the detection of sericin in cosmetics and the SOD in human serum samples. Importantly, this work represents the first chemiluminescent method for sericin detection. In addition, the system exhibited high sustainability and practical utility, as confirmed by AGREE (greenness) and BAGI (blueness) assessment tools. Furthermore, it introduces a new class of protein-based coreactants for CL systems, expanding the frontier of (bio)analytical detection.

Chemiluminescence “turn-on” detection of tyrosinase activity via in situ generation of dopamine based on a lucigenin and riboflavin system

Yi Wang,Chengpei Du,Ze Liu,Kanglin Pei,Yan Zhang,Wenjing Qi

A lucigenin and riboflavin chemiluminescence system was utilized for the first time to achieve the “turn-on” detection of tyrosinase activity via an in situ reaction between tyrosinase and tyramine to generate dopamine. Tyramine is the model substrate of tyrosinase and dopamine is the product. Since dopamine can enhance the chemiluminescence of the lucigenin and riboflavin system, the chemiluminescence of lucigenin and riboflavin can be enhanced in the presence of both tyramine and tyrosinase. In the presence of 6.0 U mL−1 tyrosinase, the chemiluminescence intensity was nearly 10 times higher than that of lucigenin, riboflavin and tyramine mixtures. Therefore, this method has been applied in the chemiluminescence “turn-on” detection of tyrosinase activity in the range of 0.1–8.0 U mL−1 with the limit of detection (LOD) of 0.028 U mL−1. This overall process of sensing tyrosinase activity took nearly 30 min. Moreover, it had high selectivity in the chemiluminescence “turn-on” detection of tyrosinase activity towards other enzymes, such as glucose oxidase, lysozyme, trypsin or alkaline phosphatase. When 1.0, 2.0 and 5.0 U mL−1 tyrosinase were added to the diluted serum samples, recoveries were in the range of 100.2%–104.1%. This indicates that this method for the chemiluminescence “turn-on” detection of tyrosinase activity has high sensitivity, selectivity, accuracy and fast response time.

In Situ Determination of Chloride Ions Using a Novel Double-Layer Membrane Optical Fiber Sensor Modified with the UiO-66-NH2/Lucigenin Complex

Chloride quantification is crucial for environmental monitoring, marine research, and the durability assessment of geotechnical infrastructures, yet accurate measurement in complex aqueous and soil matrices remains challenging. Optical fiber sensors offer distinct advantages, including resistance to electromagnetic interference, high sensitivity and low cost. Unfortunately, existing fiber-optic chloride sensors are often limited by insufficient sensitivity, poor anti-ion interference, inadequate portability, and an inability to perform long-term in situ monitoring. Herein, a novel fluorescent optical fiber chloride sensor based on UiO-66-NH2/lucigenin composite is fabricated, in which the mixture formed lucigenin encapsulated with UiO-66-NH2is immobilized within a dual-layer membrane composed of an inner cellulose acetate (CA) matrix and an outer polyvinyl alcohol (PVA) membrane. The chloride-responsive fluorescent probe operates on the principle of fluorescence quenching. The dual-layer sensitive membrane is engineered to significantly enhance sensitivity, linearity, and stability for long-term monitoring. Furthermore, the portable device eliminates the constraints of bulky optical systems and mitigates instability caused by photobleaching, enabling reliable in situ chloride detection in water, soil, and geotechnical environments. Experimental results confirm the superior analytical performance of the sensor across various soil and aquatic media. This work represents a notable advancement in the field of fluorescent optical fiber sensors and holds substantial promise for practical applications.