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High-efficiency chemiluminescence (CL) resonance energy transfer (CRET) can be obtained by shortening the donor-acceptor distance and/or improving the luminescence efficiency of CRET acceptors. However, careful design and stringent experimental conditions are usually required for the ordered assembly of CRET acceptors on support materials to avoid aggregation-caused quenching problems. In this work, an aggregation-induced emission (AIE)-active fluorophore was disorderly adsorbed on the surface of layered double hydroxides (LDHs), which could exhibit high-efficiency luminescence. On the other hand, the positively charged LDHs can further adsorb peroxynitrite (ONOO-) on the surface of LDHs. Therefore, the LDH-supported AIE fluorophore could dramatically amplify weak CL signals from ONOO- donors as a result of ultra-high CRET efficiency by coupling the shorter donor-acceptor distance with efficient CRET acceptors. The proposed CL system has been successfully applied for the detection of NaNO2 in the concentration range from 1.0 to 100 μM with a detection limit as low as 0.5 μM. Satisfactory recoveries (98-106%) and good accuracy were achieved for sausage samples. Our success will open new avenues for the convenient design of high-efficiency CRET systems.

HClO/ClO- is the most effective antibacterial active oxygen in neutrophils. However, its excessive existence often leads to the destruction of human physiological mechanisms. In recent years, the developed luminescent probes for the detection of HClO/ClO- are not only conducive to improve the sensitivity and selectivity of HClO/ClO- detection, but also play a crucial role in understanding the biological functions of HClO/ClO-. In addition, luminescent probe-based biological imaging for HClO/ClO- at sub-cellular resolution has become a powerful tool for biopathology and medical diagnostic research. This article reviews a variety of luminescent probes for the detection of HClO/ClO-in vitro and in vivo with different design principles and mechanisms, including fluorescence, phosphorescence, and chemiluminescence. The photophysical/chemical properties and biological applications of these luminescent probes were outlined. Finally, we summarized the merits and demerits of the developed luminescent probes and discussed their challenges and future development trends. It is hoped that this review can provide some inspiration for the development of luminescent probe-based strategies and to promote the further research of biomedical luminescent probes for HClO/ClO-.

The oxygen states (O-states) of carbon quantum dots (CDs) play an important role, with regard to their optical properties and analytical applications. However, the rapid screening of O-states in CDs is still a great challenge, because of the complicated surface composition. In this study, it is found that the chemiluminescence (CL) intensity of prepared CDs in the presence of peroxynitrite (ONOO-) is proportional to the content of C-O group-related O-states. The related mechanism discloses that the O-state-dependent CL is due to the fact that abundant C-O functional groups in CDs with high O-states could facilitate the electron transfer of the produced smaller energy gaps for strong CL emission. Hence, ONOO--induced CL can be utilized as a facile probe for the rapid screening of O-states in CDs with some advantages, such as rapid response, low cost, and easy operation. Its practicability is verified by detecting the CL of phosphorus-doped CDs with variable phosphorus-doping contents. The content of C-O group-related O-states in sulfur-/phosphorus-doped CDs measured by the proposed CL probe is consistent with X-ray photoelectron spectroscopy (XPS) characterization. This strategy can also be extended to distinguish O-states in different types of nanoparticles by tuning the CL probe molecules.

The emergence of aggregation-induced emission (AIE) has opened up a new avenue for scientists. There is a great demand for the development of a new generation chemiluminescence resonance energy transfer (CRET) acceptors with AIE characteristics due to the aggregation-caused chemiluminescence (CL) quenching effect commonly observed in the conventional fluorophore CL acceptors at high concentrations. However, the systematical studies involving in AIE-amplified CL are still scarce. Herein, it is the first report that the gold nanocluster aggregates (a type of well-defined AIE molecules) are used to study their influence on the bis(2,4,6-trichlorophenyl) oxalate (TCPO)-H2O2 CL reaction. Interestingly, the AIE molecules in the diluted solution are unable to boost the CL signal of the TCPO-H2O2 system, but their aggregates display a strongly enhanced CL emission compared to their counterparts of fluorophore molecules, thanks to the unique AIE effect of gold nanoclusters. In comparison to rhodamine B with the aid of an imidazole catalyst, the detection limit of the gold nanocluster aggregate-amplified CL probe for H2O2 (S/N = 3) is low in the absence of any catalyst. Finally, the other two typical AIE molecules, Au(I)-thiolate complexes and 9,10-bis[4-(3-sulfonatopropoxyl)-styryl]anthracene (BSPSA), are investigated to verify the generality of the AIE molecule-amplified CL emissions. These results demonstrate effective access to highly fluorescent AIE molecules with practical applications in avoiding the aggregation-induced CL quenching at high concentrations, which can be expected to provide a novel and sensitive platform for the CL amplified detection.

In general, the chemiluminescence (CL) sensing of vitamin B-12 is achieved by determining Co(II) liberated from acidified vitamin B-12 by a luminol system. However, the luminol system for sensing vitamin B-12 has poor selectivity due to serious interference from other metal ions. In this study, as a novel CL amplifier of the Co(II)+H2O2+OH- ultra-weak CL reaction (Fenton-like system), dodecylbenzene sulfonate (DBS)-layered double hydroxides (LDHs) have been applied to the specific determination of vitamin B-12 by liberating Co(II). The CL intensity increased with increasing the concentration of vitamin B-12 in a wide range from 1.0 ng mL(-1) to 5 mu g mL(-1) with a detection limit of 0.57 ng mL(-1) (S/N=3). The proposed method has been successfully applied to determine vitamin B-12 in egg yolk with simple procedures, shorter time and higher selectivity. Recoveries from spiked real samples were 96-103%. The results of the proposed method for sensing vitamin B12 in real samples were agreed with those obtained by the standard inductively coupled plasma mass spectrometry (ICP-MS) method. To the best of our knowledge, this is the first report on the CL sensing of vitamin B-12 with high selectivity in the absence of luminol. (C) 2014 Elsevier B.V. All rights reserved.

In this study, Co(II)-EDTA-intercalated Mg-Al layered double hydroxides (LDHs) synthesized by anion exchange method were immobilized in a clear quartz tube to fabricate a novel chemiluminescence (CL) flow-through sensor. Interestingly, this simple micro-fabricated flow cell could greatly enhance the CL signals from the luminol-H2O2 reaction. The detection limit for H2O2 (S/N = 3) was 0.14 μM. Trace metal ions in the matrix had no effect because they were easy to complex with EDTA. The proposed sensor has been successfully applied to determine H2O2 in snow water samples with simple procedures, shorter response time and higher selectivity. The results demonstrated that this proposed method had great potential in chemical/biological sensing for H2O2 as well as for other oxidase-based reactions producing H2O2. To the best of our knowledge, this is the first report on the use of metal complex-intercalated LDHs for CL signal amplification.

We report a novel approach for preparation of networked gold nanoparticles (AuNPs) using reactive oxygen species (i.e., peroxymonocarbonate, HCO(4)(-)) as a novel reducing agent, along with nonionic fluorosurfactant (FSN) assistance. The formation mechanism of the networked AuNPs is demonstrated by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV-visible spectroscopy, powder X-ray diffraction (XRD) measurement and energy dispersive X-ray spectroscopy (EDS). In this case, HCO(4)(-) serves as a reducing agent for the preparation of the networked AuNPs, and further as a strong oxidizing agent attached to the surface of networked AuNPs, which can trigger the strong CL emission from luminol without the addition of H(2)O(2). In addition, FSN can control and stabilize the crystal morphology of the networked AuNPs, and improve the selectivity of the CL detection system for aminothiols. Finally, the networked AuNPs have been applied for ultrasensitive detection of aminothiols in human urine and plasma samples.

The interlamellar dodecylbenzene sulfonate (DBS) in layered double hydroxides (LDHs) can amplify an ultraweak chemiluminescence (CL) from Fenton-like reaction (Co(II) + H2O2 + OH–). The CL enhancem...

It was found that CdTe semiconductor nanocrystals (NCs) can induce a great sensitized effect on chemiluminescence (CL) emission from peroxynitrous acid (ONOOH)-Na2CO3 system. CL spectra, fluorescence (FL) spectra, and the quenching effect of reactive oxygen species were used to investigate the CL reaction mechanism. The CL intensity was proportional to the concentration of nitrite in the range from 0.05 to 50 mu M. The detection limit (S/N = 3) was 0.024 mu M and the relative standard deviation (RSD) for five repeated measurements of 0.5 mu M nitrite was 4.2%. This method has been successfully applied to determine nitrite in well water samples with recoveries of 94.0-100.5%. This was the first work for direct (not inhibition effect) determination of analytes using semiconductor NCs-based CL sensor. (C), 2011 Elsevier B.V. All rights reserved.

Nanomaterial-amplified chemiluminescence (CL) has become a growing area of interest in recent years. We review the development of nanomaterial-amplified CL systems and their applications in bioassays. We mainly focus on nanoparticles (gold, platinum, silver, bimetallic, semiconductor and magnetic). Furthermore, we discuss some critical challenges in this field and possible solutions to overcome these challenges.

Water-soluble CdTe quantum dots (QDs) capped with three different thioalkyl acids (mercaptoacetic acid, cysteine and glutathione) were synthesized in aqueous solution. In basic media, K3Fe(CN)6 could directly oxidize the water-soluble CdTe QDs to produce strong CL emission. It was found that the CL intensity depended on the capping ligand and size of CdTe QDs. CL spectra and fluorescence spectra of the system were measured to investigate the CL reaction mechanism. Moreover, the effects of 17 metal ions on the CL system were carefully investigated. Ca2+, Co2+, Mn2+, Hg2+, Mg2+, Cu2+, Ni2+, Cr3+ and Fe3+ could markedly inhibit the CL signal of the K3Fe(CN)6–CdTe QDs system, which makes it applicable for the detection of such ions. This work is of importance for gaining a better understanding of the unique optical and physical chemistry properties of QDs, and it is also helpful to find more practical applications of QDs.