A chemical timer approach to delayed chemiluminescence.

Although the onset time of chemical reactions can be manipulated by mechanical, electrical, and optical methods, its chemical control remains highly challenging. Herein, we report a chemical timer approach for manipulating the emission onset time of chemiluminescence (CL) reactions. A mixture of Mn2+, NaHCO3, and a luminol analog with H2O2 produced reactive oxygen species (ROS) radicals and other superoxo species (superoxide containing complex) with high efficiency, accompanied by strong and immediate CL emission. Surprisingly, the addition of thiourea postponed CL emission in a concentration-dependent manner. The delay was attributed to a slow-generation-scavenging mechanism, which was found to be generally applicable not only to various types of CL reagents and ROS radical scavengers but also to popular chromogenic reactions. The precise regulation of CL kinetics was further utilized in dynamic chemical coding with improved coding density and security. This approach provides a powerful platform for engineering chemical reaction kinetics using chemical timers, which is of application potential in bioassays, biosensors, CL microscopic imaging, microchips, array chips, and informatics.

Chemiluminescent Conjugated Polymer Nanoparticles for Deep-Tissue Inflammation Imaging and Photodynamic Therapy of Cancer.

Deep-tissue optical imaging and photodynamic therapy (PDT) remain a big challenge for the diagnosis and treatment of cancer. Chemiluminescence (CL) has emerged as a promising tool for biological imaging and in vivo therapy. The development of covalent-binding chemiluminescence agents with high stability and high chemiluminescence resonance energy transfer (CRET) efficiency is urgent. Herein, we design and synthesize an unprecedented chemiluminescent conjugated polymer PFV-Luminol, which consists of conjugated polyfluorene vinylene (PFV) main chains and isoluminol-modified side chains. Notably, isoluminol groups with chemiluminescent ability are covalently linked to main chains by amide bonds, which dramatically narrow their distance, greatly improving the CRET efficiency. In the presence of pathologically high levels of various reactive oxygen species (ROS), especially singlet oxygen (1O2), PFV-Luminol emits strong fluorescence and produces more ROS. Furthermore, we construct the PFV-L@PEG-NPs and PFV-L@PEG-FA-NPs nanoparticles by self-assembly of PFV-Luminol and amphiphilic copolymer DSPE-PEG/DSPE-PEG-FA. The chemiluminescent PFV-L@PEG-NPs nanoparticles exhibit excellent capabilities for in vivo imaging in different inflammatory animal models with great tissue penetration and resolution. In addition, PFV-L@PEG-FA-NPs nanoparticles show both sensitive in vivo chemiluminescence imaging and efficient chemiluminescence-mediated PDT for antitumors. This study paves the way for the design of chemiluminescent probes and their applications in the diagnosis and therapy of diseases.

Boosting Photon Emission from the Chemiluminescence of Luminol Based on Host-Guest Recognition for the Determination of Dopamine.

Modulating the photon emission of the luminophore for boosting chemiluminescence (CL) response is very crucial for the construction of highly sensitive sensors via the introduction of functionalized materials. Herein, the integration of the emitter and coreactant accelerator into one entity is realized by simply assembling cucurbit[7]uril (CB[7]) on the surface of gold nanoparticles (AuNPs) through simple assembly via a Au-O bond. The loaded CB[7] on the AuNPs improves their catalytic capacity for the generation of hydroxyl radicals(•OH). Moreover, the host-guest recognition interaction between luminol and CB[7] enables the capture of luminol on AuNPs efficiently. Also, the intramolecular electron-transfer reaction between the luminol and •OH enables the CL response more effectively in the entity, which greatly boosts photon emission ca 100 folds compared with the individual luminol/H2O2. The host-guest recognition between luminol and CB[7] is revealed by Fourier transform infrared spectroscopy, electrochemical, and thermogravimetric characterization. Moreover, the proposed CL system is successfully used for the sensitive and selective determination of dopamine (DA) based on a synergistic quenching mechanism including the competition quenching and radical-scavenging effect from DA. The present amplified strategy by integrating recognized and amplified elements within one entity simplifies the sensing process and holds great potential for sensitive analysis based on the self-enhanced strategies.

Photocatalytic Aptamer Chemiluminescent System for a Homogeneous, Reliable, Label-Free, Generic Assay of Small Molecules.

Chemiluminescence is a powerful analytical technique with many advantages, while aptamers are well-known as good molecular recognition units. However, many aptamer-based chemiluminescence assays employed interface sensing, which often needed several immobilization, separation, and washing steps. To minimize the risks of contamination and false-positive, we for the first time proposed a photocatalytic aptamer chemiluminescent system for a homogeneous, label-free, generic assay of small molecules. After binding to a DNA aptamer, thioflavin T has a unique photocatalytic oxidase activity to activate the system's luminol chemiluminescence. Then, the specific binding between the aptamer and target molecules will compete with the above process. Therefore, we can realize the efficient assay of different analytes including estradiol and adenosine. Such a homogeneous chemiluminescent system allowed a direct assay of small molecules with limits of detection in a nM level. Several control tests were carried out to avoid possible false-positive results, which were originated from the interactions between analytes and sensing interfaces previously. This homogeneous chemiluminescent system provides a useful strategy to reliably assay various analytes in the pharmacy or biology field.

Boosting Electrochemiluminescence Performance of a Dual-Active Site Iron Single-Atom Catalyst-Based Luminol-Dissolved Oxygen System via Plasmon-Induced Hot Holes.

Due to the commonly low content of biomarkers in diseases, increasing the sensitivity of electrochemiluminescence (ECL) systems is of great significance for in vitro ECL diagnosis and biodetection. Although dissolved O2 (DO) has recently been considered superior to H2O2 as a coreactant in the most widely used luminol ECL systems owing to its improved stability and less biotoxicity, it still has unsatisfactory ECL performance because of its ultralow reactivity. In this study, an effective plasmonic luminol-DO ECL system has been developed by complexing luminol-capped Ag nanoparticles (AgNPs) with plasma-treated Fe single-atom catalysts (Fe-SACs) embedded in graphitic carbon nitride (g-CN) (pFe-g-CN). Under optimal conditions, the performance of the resulting ECL system could be markedly increased up to 1300-fold compared to the traditional luminol-DO system. Further investigations revealed that duple binding sites of pFe-g-CN and plasmonically induced hot holes that disseminated from AgNPs to g-CN surfaces lead to facilitate significantly the luminous reaction process of the system. The proposed luminol-DO ECL system was further employed for the stable and ultrasensitive detection of prostate-specific antigen in a wide linear range of 1.0 fg/mL to 1 µg/mL, with a pretty low limit of detection of 0.183 fg/mL.

Cu Single-Atom Nanozyme-Mediated Electrochemiluminescence Biosensor for Highly Sensitive Detection of MicroRNA-622.

MicroRNA (miRNA) detection is a critical aspect of disease diagnosis, and recent studies indicate that miRNA-622 could be a potential target for lung cancer. Herein, Cu single atoms were anchored on graphitic carbon nitride (Cu SAs@CN) as a coreaction accelerator applied in luminol-H2O2 system, thereby establishing an efficient and sensitive electrochemiluminescence (ECL) biosensor for miRNA-622 detection. Cu SAs@CN was explored to possess excellent enzyme-like activities that promote the generation of abundant reactive oxygen species, which amplified ECL emission. Meanwhile, in order to improve the accuracy and sensitivity for miRNA-622 detection, the highly specific trans-cleavage ability of CRISPR/Cas12a was combined with a catalytic hairpin assembly strategy. Therefore, an ECL biosensor for miRNA-622 detection was systematically constructed as a proof of concept, achieving an ultralow limit of detection of 1.09 fM, and the feasibility was demonstrated in human serum samples. The findings of this research provide a promising strategy to enhance the ECL response using versatile single-atom catalysts, thus advancing the development of ECL biosensing applications.

Silica Nanochannels as Nanoreactors for the Confined Synthesis of Ag NPs to Boost Electrochemical Stripping Chemiluminescence of the Luminol-O2 System for the Sensitive Aptasensor.

Herein, we, for the first time, synthesize silver nanoparticles (Ag NPs) within the nanochannels of amino group-functionalized vertically ordered mesoporous silica films (NH2-VMSF) and investigate their coreaction accelerator role in the luminol-dissolved oxygen (O2) electrochemical stripping chemiluminescence (ESCL) system. The synthesized Ag NPs are capable of electrocatalytic reduction of O2 to superoxide radicals, and meanwhile, sliver ions (Ag+) electrochemically stripped from Ag NPs can promote the amount of luminol anion radicals, generating the boosted ECL intensity of the luminol-dissolved O2 system. This proposed Ag NPs@NH2-VMSF on the indium tin oxide electrode was applied to construct the ESCL aptasensor for quantitative determination of prostate-specific antigen (PSA), yielding a low detection limit [0.19 pg/mL (S/N = 3)] and a broad linear dynamic range (1 pg/mL to 100 ng/mL). Furthermore, good analytical performance of PSA in serum with satisfactory recoveries and low relative standard deviation values is achieved by our developed ESCL aptasensor, rendering it a convenient and sensitive method for PSA determination in clinical applications and further broadening the strategy of ESCL techniques.

Hemin as a Molecular Probe for Nitric Oxide Detection in Physiological Solutions: Experimental and Theoretical Assessment.

Given its pivotal role in modulating various pathological processes, precise measurement of nitric oxide (●NO) levels in physiological solutions is imperative. The key techniques include the ozone-based chemiluminescence (CL) reactions, amperometric ●NO sensing, and Griess assay, each with its advantages and drawbacks. In this study, a hemin/H2O2/luminol CL reaction was employed for accurately detecting ●NO in diverse solutions. We investigated how the luminescence kinetics was influenced by ●NO from two donors, nitrite and peroxynitrite, while also assessing the impact of culture medium components and reactive species quenchers. Furthermore, we experimentally and theoretically explored the mechanism of hemin oxidation responsible for the initiation of light generation. Although both hemin and ●NO enhanced the H2O2/luminol-based luminescence reactions with distinct kinetics, hemin's interference with ●NO/peroxynitrite- modulated their individual effects. Leveraging the propagated signal due to hemin, the ●NO levels in solution were estimated, observing parallel changes to those detected via amperometric detection in response to varying concentrations of the ●NO-donor. The examined reactions aid in comprehending the mechanism of ●NO/hemin/H2O2/luminol interactions and how these can be used for detecting ●NO in solution with minimal sample size demands. Moreover, the selectivity across different solutions can be improved by incorporating certain quenchers for reactive species into the reaction.

Controlled-Release Electrochemiluminescence Biosensor with Strong Self-On Effect by a Multiple Signal Amplification Strategy for Trace Detection of Prostate-Specific Antigen.

The enhancement of sensitivity in biological analysis detection can reduce the probability of false positives of the biosensor. In this work, a novel self-on controlled-release electrochemiluminescence (CRE) biosensor was designed by multiple signal amplification and framework-enhanced stability strategies. As a result, the changes of the ECL signal were enhanced before and after the controlled-release process, achieving sensitive detection of prostate-specific antigen (PSA). Specifically, for one thing, Fe3O4@CeO2-NH2 with two paths for enhancing the generation of coreactant radicals was used as the coreaction accelerator to boost ECL performance. For another, due to the framework stability, zeolitic imidazolate framework-8-NH2 (ZIF-8-NH2) was combined with luminol to make the ECL signal more stable. Based on these strategies, the constructed CRE biosensor showed a strong self-on effect in the presence of PSA and high sensitivity in a series of tests. The detection range and limit of detection (LOD) were 5 fg/mL to 10 ng/mL and 2.8 fg/mL (S/N = 3), respectively, providing a feasible approach for clinical detection of PSA.

Ascorbate peroxidase 1 allows monitoring of cytosolic accumulation of effector-triggered reactive oxygen species using a luminol-based assay.

Biphasic production of reactive oxygen species (ROS) has been observed in plants treated with avirulent bacterial strains. The first transient peak corresponds to pattern-triggered immunity (PTI)-ROS, whereas the second long-lasting peak corresponds to effector-triggered immunity (ETI)-ROS. PTI-ROS are produced in the apoplast by plasma membrane-localized NADPH oxidases, and the recognition of an avirulent effector increases the PTI-ROS regulatory module, leading to ETI-ROS accumulation in the apoplast. However, how apoplastic ETI-ROS signaling is relayed to the cytosol is still unknown. Here, we found that in the absence of cytosolic ascorbate peroxidase 1 (APX1), the second phase of ETI-ROS accumulation was undetectable in Arabidopsis (Arabidopsis thaliana) using luminol-based assays. In addition to being a scavenger of cytosolic H2O2, we discovered that APX1 served as a catalyst in this chemiluminescence ROS assay by employing luminol as an electron donor. A horseradish peroxidase (HRP)-mimicking APX1 mutation (APX1W41F) further enhanced its catalytic activity toward luminol, whereas an HRP-dead APX1 mutation (APX1R38H) reduced its luminol oxidation activity. The cytosolic localization of APX1 implies that ETI-ROS might accumulate in the cytosol. When ROS were detected using a fluorescent dye, green fluorescence was observed in the cytosol 6 h after infiltration with an avirulent bacterial strain. Collectively, these results indicate that ETI-ROS eventually accumulate in the cytosol, and cytosolic APX1 catalyzes luminol oxidation and allows monitoring of the kinetics of ETI-ROS in the cytosol. Our study provides important insights into the spatial dynamics of ROS accumulation in plant immunity.

Luminol and the postmortem interval estimation - influence of taphonomic factors.

The estimation of the postmortem interval (PMI) is one of the key challenges for forensic anthropologists. Although there are several methods referenced for this purpose, none is sufficiently effective. One of the main reasons justifying the complexity of this task is the influence of several taphonomic factors.The study of the Luminol technique has stood out as a promising method for estimating PMI, complementing the existing methods, since it is an economic, easy and reproducible method that operates as a presumptive test. However, it is not known which taphonomic factors can influence the results obtained by this technique.The aim of this study is to test the influence of taphonomic factors, such as temperature, humidity, soil type and pH, on the estimation of the PMI by the Luminol technique.In order to test the influence of the referred factors, a sample consisting of 30 clavicles, with known and similar PMI, collected from autopsies, was distributed as evenly as possible by six vases and buried with different decomposition conditions for a period of 12 months. After the exhumation and sample preparation, the Luminol technique was applied.It was possible to clearly observe differences in the results. Thus, according to our research, it is possible to conclude that the results obtained by the application of Luminol are influenced by taphonomic factors. Therefore, the context in which a body is found should always be considered for applying this technique.

Cathodic electrochemiluminescence of L012 and its application in antioxidant detection.

Cathodic electrochemiluminescence (ECL) of a luminol (or its analogues)-dissolved oxygen (O2) system is an ideal alternative to ECL of the traditional luminol-hydrogen peroxide (H2O2) system, which can efficiently avoid the self-decomposition of H2O2 at room temperature. However, the mechanism for the generation of cathodic ECL by the luminol (or its analogues)-O2 system is still ambiguous. Herein, we report the study of cathodic ECL generation by the L012-O2 system at a glassy carbon electrode (GCE). The types of reactive oxygen species (ROS) involved generated during ECL reactions were verified. A possible reaction mechanism for the system was proposed and the rate constants of related reactions were estimated. Furthermore, several intermediates of L012 involved in the proposed pathways were validated by electrochemistry-coupled mass spectrometry. Finally, the cathodic ECL system was successfully used for measuring the antioxidant capacity of commercial juice with Trolox as a standard.

Evaluating early apoptosis-related cellular MiRNAs with an ultrasensitive electrochemiluminescence nanoplatform.

It is known that the abnormal expression of specific cellular miRNAs is closely related to cell apoptosis, and so monitoring the level change of these miRNAs can in principle be used to evaluate the process of apoptosis stimulated by drugs. Towards this goal, here we construct an ultrasensitive electrochemiluminescence (ECL) nanoplatform via the target miRNA-triggered immobilization of spherical nucleic acid enzymes (SNAzymes) onto tetrahedral DNA nanostructures on the electrode surface, which catalyzes the luminol-H2O2 reaction to output an ECL signal. This enables the sensitive and specific detection of two apoptosis-related miRNAs, miR-21 and miR-133a, with a detection limit of 33 aM. Furthermore, we employed the developed ECL nanoplatform to monitor the levels of these two miRNAs inside cancer cells stimulated by DOX, showing that the level of miR-21 decreases, while that of miR-133a increases in the early apoptotic cells. This difference highlights the distinct roles of the two target miRNAs, where miR-21 promotes the early apoptosis of cancer cells, whereas miR-133a suppresses it, providing new insight into cell physiological processes.

Wireless rotating bipolar electrochemiluminescence for enzymatic detection.

New dynamic, wireless and cost-effective analytical devices are developing rapidly in biochemical analysis. Here, we report on a remotely-controlled rotating electrochemiluminescence (ECL) sensing system for enzymatic detection of a model analyte, glucose, on both polarized sides of an iron wire acting as a bipolar electrode. The iron wire is controlled by double contactless mode, involving remote electric field polarization, and magnetic field-induced rotational motion. The former triggers the interfacial polarization of both extremities of the wire by bipolar electrochemistry, which generates ECL emission of the luminol derivative (L-012) with the enzymatically produced hydrogen peroxide in presence of glucose, at both anodic and cathodic poles, simultaneously. The latter generates a convective flow, leading to an increase in mass transfer and amplifying the corresponding ECL signals. Quantitative glucose detection in human serum samples is achieved. The ECL signals were found to be a linear function of the glucose concentration within the range of 10-1000 µM and with a limit of detection of 10 µM. The dynamic bipolar ECL system simultaneously generates light emissions at both anodic and cathodic poles for glucose detection, which can be further applied to biosensing and imaging in autonomous devices.

In vitro assessment of thyroid peroxidase inhibition by chemical exposure: comparison of cell models and detection methods.

Disruption of the thyroid hormone (TH) system is connected with diverse adverse health outcomes in wildlife and humans. It is crucial to develop and validate suitable in vitro assays capable of measuring the disruption of the thyroid hormone (TH) system. These assays are also essential to comply with the 3R principles, aiming to replace the ex vivo tests often utilised in the chemical assessment. We compared the two commonly used assays applicable for high throughput screening [Luminol and Amplex UltraRed (AUR)] for the assessment of inhibition of thyroid peroxidase (TPO, a crucial enzyme in TH synthesis) using several cell lines and 21 compounds from different use categories. As the investigated cell lines derived from human and rat thyroid showed low or undetectable TPO expression, we developed a series of novel cell lines overexpressing human TPO protein. The HEK-TPOA7 model was prioritised for further research based on the high and stable TPO gene and protein expression. Notably, the Luminol assay detected significant peroxidase activity and signal inhibition even in Nthy-ori 3-1 and HEK293T cell lines without TPO expression, revealing its lack of specificity. Conversely, the AUR assay was specific to TPO activity. Nevertheless, despite the different specificity, both assays identified similar peroxidation inhibitors. Over half of the tested chemicals with diverse structures and from different use groups caused TPO inhibition, including some widespread environmental contaminants suggesting a potential impact of environmental chemicals on TH synthesis. Furthermore, in silico SeqAPASS analysis confirmed the high similarity of human TPO across mammals and other vertebrate classes, suggesting the applicability of HEK-TPOA7 model findings to other vertebrates.

Quantitative analysis of CL-20 explosive by smartphone-based chemiluminescence method.

A new smartphone-based chemiluminescence method has been introduced for the quantitative analysis of CL-20 (Hexanitroazaisowuertzitan) explosive. The solvent mixture, oxidizer agent, and concentration of the reactants were optimized using statistical procedures. CL-20 explosive showed a quenching effect on the chemiluminescence intensity of the luminol-NaClO reaction in the solvent mixture of DMSO/H2O. A smartphone was used as a detector to record the light intensity of chemiluminescence reaction as a video file. The recorded video file was converted to an analytical signal as intensity luminescence-time curve by a written code in MATLAB software. Dynamic range and limit of detection of the proposed method were obtained 2.0-240.0 and 1.1 mg⋅L-1, respectively, in optimized concentrations 1.5 × 10-3 mol⋅L-1 luminol and 1.0 × 10-2 mol⋅L-1 NaClO. Precursors TADB, HBIW, and TADNIW in CL-20 explosive synthesis did not show interference in measurement the CL-20 purity. The analysis of CL-20 spiked samples of soil and water indicated the satisfactory ability of the method in the analysis of real samples. The interaction of CL-20 molecules and OCl- ions is due to quench of chemiluminescence reaction of the luminol-NaClO.

FeS2 nanosheets-luminol-O2 chemiluminescence method for determination of venlafaxine hydrochloride, imipramine hydrochloride, and cefazolin sodium.

This study introduces a novel chemiluminescence (CL) approach utilizing FeS2 nanosheets (NSs) catalyzed luminol-O2 CL reaction for the measurement of three pharmaceuticals, namely venlafaxine hydrochloride (VFX), imipramine hydrochloride (IPM), and cefazolin sodium (CEF). The CL method involved the phenomenon of quenching induced by the pharmaceuticals in the CL reaction. To achieve the most quenching efficacy of the pharmaceuticals in the CL reaction, the concentrations of reactants comprising luminol, NaOH, and FeS2 NSs were optimized accordingly. The calibration curves demonstrated exceptional linearity within the concentration range spanning from 4.00 × 10-7 to 1.00 × 10-3 mol L-1, 1.00 × 10-7 to 1.00 × 10-4 mol L-1, and 4.00 × 10-6 to 2.00 × 10-4 mol L-1 with detection limits (3σ) of 3.54 × 10-7, 1.08 × 10-8, and 2.63 × 10-6 mol L-1 for VFX, IPM, and CEF, respectively. This study synthesized FeS2 NSs using a facile hydrothermal approach, and then the synthesized FeS2 NSs were subjected to a comprehensive characterization using a range of spectroscopic methods. The proposed CL method was effective in measuring the aforementioned pharmaceuticals in pharmaceutical formulations as well as different water samples. The mechanism of the CL system has been elucidated.

A dual amplified gold nanoparticle-based biosensor for ultrasensitive and selective detection of fibrin.

Ultrasensitive, selective, and non-invasive detection of fibrin in human serum is critical for disease diagnosis. So far, the development of high-performance and ultrasensitive biosensors maintains core challenges for biosensing. Herein, we designed a novel ribbon nanoprobe for ultrasensitive detection of fibrin. The probe contains gold nanoparticles (AuNPs) that can not only link with homing peptide Cys-Arg-Glu-Lys-Ala (CREKA) to recognize fibrin but also carry long DNA belts to form G-quadruplex-based DNAzyme, catalyzing the chemiluminescence of luminol-hydrogen peroxide (H2O2) reaction. Combined with the second amplification procedure of rolling circle amplification (RCA), the assay exhibits excellent sensitivity with a detection limit of 0.04 fmol L-1 fibrin based on the 3-sigma. Furthermore, the biosensor shows high specificity on fibrin in samples because the structure of antibody-fibrin-homing peptide was employed to double recognize fibrin. Altogether, the simple and inexpensive approach may present a great potential for reliable detection of biomarkers.

A molecule-imprinted electrochemiluminescence sensor based on CdS@MWCNTs for ultrasensitive detection of fenpropathrin.

A molecularly-imprinted electrochemiluminescence sensor was constructed for the determination of fenpropathrin (FPT) by molecular imprinting technology. In this sensing platform, the introduction of CdS@MWCNTs significantly enhanced the initial ECL signal of the luminol-O2 system. Specifically, MWCNTs was used as a carrier to adsorb more CdS, in which CdS acted as a co-reaction promoter for luminescence. Molecularly imprinted polymer (MIP) containing specific recognition sites of FPT was used as the material for selective recognition. With increasing amount of FPT the ECL signal decreased. Under the optimum conditions, the ECL response was linearly related to the logarithm of FPT concentration. The developed ECL sensor allowed for sensitive determination of FPT and exhibited a wide linear range from 1.0 × 10- 10 mol L- 1 to 1.0 × 10- 6 mol L- 1. The limit of detection was 3.3 × 10- 11 mol L- 1 (S/N = 3). It can be used for the detection of FPT in vegetable samples.

Molecularly imprinted electrochemiluminescence sensor based on a novel luminol derivative for detection of human serum albumin via click reaction.

A novel luminol derivative of N-(1,4-dioxo-1,2,3,4-tetrahydrophthalazin-5-yl)acrylamide (DTA) with excellent luminescence efficiency was designed and synthesized. Furthermore, a molecularly imprinted electrochemiluminescence sensor (MIECLS) was fabricated to detect ultratrace levels of human serum albumin (HSA) with high sensitivity and selectivity via a click reaction. The molecularly imprinted polymers (MIPs) were formed on the electrode surface via electropolymerization with HSA as a template molecule and catechol as a monomer. In the detection process, the -SH group of HSA on the electrode and the C = C bond of acryloyl group in DTA formed a new C-S bond via the Michael addition reaction to construct the MIECLS. The higher the concentration of HSA, the greater electrochemiluminescence (ECL) intensity measured. Taking advantage of MIECLS for ECL detection (scanning potential, - 0.4 to 0.5 V), there was a good linear relationship between ECL intensity and the logarithm of HSA concentration in the range 5 × 10-9 to 1 × 10-13 mg mL-1. The limit of detection (LOD) of the sensor was 1.05 × 10-15 mg mL-1. The sensor exhibited outstanding selectivity and stability. The sensor was applied to detect HSA in human serum with good recoveries of 97.7-105.2%. The concentration of HSA was detected by electrochemical method using the gating effect of MIP.