Detection Of Neuron-specific Enolase Research Articles

A sandwich−type photoelectrochemical sensor constructed with a signal amplification strategy based on the upconversion luminescence characteristics of Ag@N−CQDs for sensitive detection of neuron specific enolase

In this paper, Bi2S3/AgBiS2 composite nanomaterials and PDA@Ag@N−CQDs were synthesized, and used as substrates and second antibody label respectively to construct a sandwich photoelectrochemical (PEC) sensor. The upconversion luminescence effect of N−CQDs can convert long wavelength light into short wavelength light that can be utilized by the substrate material, which can provide additional excitation light energy for the substrate material and further enhance the photoelectric response. Besides, Ag has SPR effect and can also promote electron transfer. The proposed sandwich immunosensor achieves detection of NSE in the concentration range of 0.001 ng mL−1 to 100 ng mL−1, with a detection limit of 0.28 pg mL−1 (S/N = 3). What's more, the proposed sensor also exhibits good stability, selectivity, as well as reproducibility, indicating its promising application prospects.

Efficient CdIn2S4/MgIn2S4 heterojunction for ultrasensitive detection of lung cancer marker neuron-specific enolase

In this work, a photoelectrochemical (PEC) immunosensor was constructed for the ultrasensitive detection of lung cancer marker neuron-specific enolase (NSE) based on a microflower-like heterojunction of cadmium indium sulfide and magnesium indium sulfide (CdIn2S4/MgIn2S4, CMIS) as photoactive material. Specifically, the well-matched energy level structure and narrow energy level gradients between CdIn2S4 and MgIn2S4 could accelerate the separation of electron-hole (e−-h+) pairs in the CMIS heterojunction to enhance the photocurrent of CMIS, which was increased 5.5 and 80 times compared with that of single CdIn2S4 and MgIn2S4, respectively. Meanwhile, using CMIS as photoactive material, increasing the biocompatibility by dropping Pt NPs on the surface of CMIS to immobilize the antibody through Pt–N bond. Fe3O4-Ab2, acting as the quencher, competitively consumes electron donors and absorbs light, leading to photocurrent quenching. With the increasing of quencher, the photocurrent decreased. Hence, the developed “signal-off” PEC immunosensor realized the trace detection of NSE within the range from 1.0 fg/mL to 10 ng/mL with a low detection limit of 0.34 fg/mL. This strategy provided a new perspective for establishing ternary metal sulfide heterojunction to construct PEC immunosensor for sensitive detection of disease biomarkers.

Clinical value of serum neuron-specific enolase in sepsis-associated encephalopathy: a systematic review and meta-analysis

ObjectiveThis study aimed to investigate the serum levels of neuron-specific enolase (NSE) in sepsis-associated encephalopathy (SAE) and perform a meta-analysis to assess the diagnostic and prognostic potential of serum NSE in SAE patients.MethodsWe searched English and Chinese databases for studies related to SAE that reported serum NSE levels until November 2023. We extracted information from these studies including the first author and year of publication, the number of samples, the gender and age of patients, the collection time of blood samples in patients, the assay method of serum NSE, the study methods, and the levels of serum NSE with units of ng/mL. The quality assessment of diagnostic accuracy studies 2 (QUADAS-2) tool was used to evaluate the study quality. A meta-analysis was performed using Review Manager version 5.3, employing either a random effects model or a fixed effects model.ResultsA total of 17 studies were included in the final meta-analysis, including 682 SAE patients and 946 NE patients. The meta-analysis demonstrated significantly higher serum NSE levels in SAE patients compared to NE patients (Z = 5.97, P < 0.001, MD = 7.79, 95%CI 5.23–10.34), irrespective of the method used for serum NSE detection (Z = 6.15, P < 0.001, mean difference [MD] = 7.75, 95%CI 5.28–10.22) and the study methods (Z = 5.97, P < 0.001, MD = 7.79, 95%CI 5.23–10.34). Furthermore, sepsis patients with a favorable outcome showed significantly lower levels of serum NSE compared to those with an unfavorable outcome (death or adverse neurological outcomes) (Z = 5.44, P < 0.001, MD = − 5.34, 95%CI − 7.26–3.42).ConclusionThe Serum level of NSE in SAE patients was significantly higher than that in septic patients without encephalopathy. The higher the serum NSE level in SAE patients, the higher their mortality rate and incidence of adverse neurological outcomes.

New electrocatalyst of Ni6MnO8@AB/PtNPs with efficient synergistic enhancement in electrochemical aptasensor for sensitive detection of neuron specific enolase

As one of the specific markers for small cell lung cancer (SCLC), the clinical value for serum neuron-specific enolase (NSE) detection in diagnosis, monitoring and therapy of SCLC is considerable. Herein, a sensitive amperometric aptasensor was developed for the detection of NSE based on nickel-manganese oxide@acetylene black/platinum nanoparticles (Ni6MnO8@AB/PtNPs) composite as signal amplifier. The combination of Ni6MnO8, AB and PtNPs not only showed synergistically catalytic activity to hydrogen peroxide (H2O2), but also possessed lots of binding sites for loading the thiol-terminated signal probes (TSPs) through Pt-S bonds. Additionally, nitrogen-doped carbon nanotubes/poly (diallyldimethylammonium chloride)/ZnO microflowers (N-CNTs/P/ZnO MFs) exhibited outstanding electric conductivity and was used as substrate material to load more biotin-terminated capture probes (BCPs). In the presence of the NSE, the TSPs and BCPs specifically recognized the NSE to form a sandwich-type electrochemical aptasensor, which exhibited a broad linear response range from 0.00001 ∼ 100 ng mL−1 and a low detection limit of 2.86 fg mL−1 (S/N = 3). In addition, the electrochemical aptasensor obtained favorable detection results in diluted human serum, indicating that it had potential application in clinical NSE detection.

Wireless Gold/Boron-Nitrogen-Codoped Graphene-Based Antenna Immunosensor for the Rapid Detection of Neuron-Specific Enolase.

Tumor-marker immunosensors for rapid on-site detection have not yet been developed because of immunoreaction bottlenecks, such as shortening the reaction time and facilitating incubation. In this study, a gold-boron-nitrogen-codoped graphene (Au-BNG)-based immunosensor antenna was constructed for the rapid detection of neuron-specific enolase (NSE). A Au-BNG radiation electrode with dual functions of antibody protein fixation and signal transmission was developed for the first time. A radiation sample cell was constructed by embedding a radiation electrode into the groove of a poly(dimethylsiloxane) dielectric substrate. The constructed sense antenna achieves accurate detection of NSE with a range from 50 fg mL-1 to 40,000 pg mL-1 and a limit of detection of 10.99 fg mL-1, demonstrating excellent selectivity, stability, and reliability. The tumor-marker detection meter can provide NSE detection results as rapidly as within 2 min by using the new strategy of the microwave self-incubation of tumor markers. This antenna immunosensor is suitable for rapid detection in outpatient clinics and can be developed into household tumor-marker detectors, which would be significant in the early detection, long-term monitoring, and efficacy evaluation of tumors.

Highly sensitive “off-on” sensor based on MXene and magnetic microspheres for simultaneous detection of lung cancer biomarkers - Neuron specific enolase and carcinoembryonic antigen

In this work, a highly sensitive lung cancer biomarkers detection probe was developed based on Ag and MXene co-functionalized magnetic microspheres. By using carboxyl magnetic microspheres as carrier, MXene was coated repeatedly by Poly (allylamine hydrochloride) (PAH) as interlayer adhesive, and silver particles grown on the surface of MXene in situ can efficiently improve the sensitivity of the probe. The detection of neuron specific enolase (NSE) is mainly through the formation of a specific complex between NSE antigen and antibody, and the release of antibody labeled with amino carbon quantum dots (CQDs) from the surface of Ag nanoparticles (AgNPs), so that the fluorescence is restored and "OFF-ON" is formed. The biosensor exhibits excellently wide linear range (0.0001–1500 ng/mL) and the limit of detection (LOD) is up to 0.03 pg/mL, which is superior to most tumor marker probes based on fluorescence mechanism. Furthermore, we constructed dual detection strategy for NSE and carcinoembryonic antigen (CEA) simultaneously.

Novel immunosensor based on electrochemiluminescence inner filter effect and static quenching between fibrillary Ag-MOGs and SiO2@PANI@AuNPs for enabling the sensitive detection of neuron-specific enolase.

Metal-organic gels (MOGs) are unique supramolecular gels that are convenient to synthesize. In this work, a cathodic electrochemiluminescence (ECL) system based on Ag-MOGs as a luminophore and K2S2O8 as a co-reactor was developed. The ECL spectrum of the Ag-MOGs overlapped significantly with the strong UV-Vis spectrum of the SiO2@PANI@AuNPs, which effectively quenched the ECL luminescence of the Ag-MOGs. Relying on theinner filter effect between Ag-MOGs and SiO2@PANI@AuNPs, a novel ECL-IFE immunosensor was developed for the detection of neuron-specific enolase (NSE). Under optimal conditions, the ECL signal of the immunosensor displayed excellent linearity over the NSE concentration range of 10 fg/mL-100 ng/mL. The limit of detection (LOD) was 2.6 fg/mL (S/N = 3) with a correlation coefficient R2 of 0.9975. The ECL immunosensor also exhibited excellent stability and reproducibility for the detection of NSE. The results reported provide afeasible concept for the development analytical methods for the detection of other clinically relevant biomarkers.

Novel electrochemical platform based on C3N4-graphene composite for the detection of neuron-specific enolase as a biomarker for lung cancer

Lung cancer remains the leading cause of cancer mortality worldwide. Small cell lung cancer (SCLC) accounts for 10–15% of cases and has an overall 5-years survival rate of only 15%. Neuron-specific enolase (NSE) has been identified as a useful biomarker for early SCLC diagnosis and therapeutic monitoring. This work reports an electrochemical immunosensing platform based on a graphene-graphitic carbon nitride (g-C3N4) nanocomposite for ultrasensitive NSE detection. The g-C3N4 nanosheets and graphene nanosheets were synthesized via liquid exfoliation and integrated through self-assembly to form the nanocomposite. This nanocomposite was used to modify screen-printed carbon electrodes followed by covalent immobilization of anti-NSE antibodies. The unique properties of the graphene-g-C3N4 composite facilitated efficient antibody loading while also enhancing electron transfer efficiency and electrochemical response. Systematic optimization of experimental parameters was performed. The immunosensor exhibited a wide linear detection range of 10 pg/mL to 100 ng/mL and low limit of detection of 3 pg/mL for NSE along with excellent selectivity against interferences. Real serum matrix analysis validated the applicability of the developed platform for sensitive and accurate NSE quantifica-tion at clinically relevant levels. This novel graphene-g-C3N4 nanocomposite based electro-chemical immunoassay demonstrates great promise for early diagnosis of SCLC.

A signal amplifying photoelectrochemical immunosensor based on the synergism of Au@CoFe2O4 and CdS/NiCo2O4 for the sensitive detection of neuron-specific enolases

Neuron-specific enolase (NSE), a marker of small cell lung cancer, is over-expressed in patient serum. To reduce the threat of lung cancer to human health and life, a rapid and effective method for the sensitive detection of NSE is necessary. In this study, a sandwich-type photoelectrochemical (PEC) immunosensor for the rapid and sensitive detection of NSE was constructed. To provide a powerful and stable photocurrent signal, the bandgap-matched CdS/NiCo2O4 was used as the substrate material. In addition, Au@CoFe2O4, which can form a step electron transfer mode with NiCo2O4, was proposed for the first time as a second antibody (Ab2) marker to amplify photoelectric signals. The constructed signal-amplified PEC immunosensor showed good linearity in the range of 1 pg/mL − 100 ng/mL with a detection limit as low as 0.24 pg/mL (S/N=3). The constructed PEC immunosensor has shown excellent stability, selectivity, reproducibility, and repeatability. It showed recoveries in the range of 98% − 105% and relative standard deviations (RSD) within 5% in sample analysis. The method proposed in this study is expected to be more widely used in the future for the detection of other disease markers as well as environmental pollutants.

A hemin/rGO/MWCNT nanocomposite-based dual signal electrochemical aptasensor for sensitive detection of NSE.

Neuron-specific enolase (NSE), a tumor marker of small cell lung cancer (SCLC), has high application value in the early diagnosis of SCLC. In this study, a dual signal electrochemical aptasensor for NSE was constructed based on hemin/reduced graphene oxide/multi-walled carbon nanotube (H-rGO-MWCNT) nanocomposites. Hemin played a dual role, functioning not only as an in situ electrochemical probe but also exhibiting excellent peroxidase-like properties, effectively catalyzing the electroreduction of H2O2. Reduced graphene oxide and multi-walled carbon nanotubes exhibited excellent conductivity. Through their binding with hemin, the nanocomposites achieved a larger specific surface area, providing numerous active sites for capturing the NSE aptamer. In the presence of NSE, the specific adsorption between the antigen and the aptamer formed a stable antigen-aptamer structure, which inhibited the performance of hemin, resulting in the weakening of the electrochemical signals of hemin and H2O2. Leveraging these characteristics, the sensitive and cost-effective dual-signal electrochemical aptasensor has been fabricated for the detection of NSE. One signal corresponded to differential pulse voltammetry (DPV) of hemin, while the other signal was derived from chronoamperometry, capturing the catalytic reduction of H2O2. The linear ranges for NSE were 1 pg mL-1 to 1 μg mL-1 and 100 pg mL-1 to 100 ng mL-1 with the limit of detection (LOD) of 0.21 pg mL-1 and 11.22 pg mL-1 by DPV and chronoamperometry, respectively. In addition, this aptasensor exhibited good reproducibility, stability and specificity. The recovery of NSE in human blood serum samples was from 89% to 131%. It provided a promising strategy for the detection of NSE in clinical diagnostics.

Ultrasensitive detection of NSE employing a novel electrochemical immunosensor based on a conjugated copolymer.

In the current study a simple and highly specific label-free impedimetric neuron specific enolase (NSE) immunosensor based on a copolymer matrix-coated disposable electrode was designed and tested. The copolymer matrix was prepared using a very conductive EDOT monomer and semi-conductive thiophene-bearing epoxy groups (ThEp), and the combination of the two monomers enhanced the conductivity and protein loading capacity of the electrode surface. The P(ThEp-co-EDOT) copolymer matrix was prepared via a drop-casting process and anti-NSE recognition biomolecules were immobilized directly on the epoxy groups of the copolymer. After the coupling of NSE molecules on the P(ThEp-co-EDOT) copolymer matrix-coated electrode surface, the charge transfer resistance (Rct) of the biosensor changed dramatically. These changes in Rct were proportional to the NSE molecule amounts captured by anti-NSE molecules. Under optimized experimental conditions, the increment in the Rct value was proportional to the NSE concentration over a range of 0.01 to 25 pg mL-1 with a detection limit (LOD) of 2.98 × 10-3 pg mL-1. This copolymer-coated electrode provided a lower LOD than the other biosensors. In addition, the suggested electrochemical immuno-platform showed good selectivity, superior reproducibility, long-term stability, and high recovery of NSE in real serum (95.64-102.20%) and saliva (95.28-105.35%) samples. These results showed that the present system had great potential for electrochemical biosensing applications.

Neuron specific enolase assay based on the perovskite CoSn(OH)6 for enhancing the anodic electrochemiluminescence of luminol

Electrochemiluminescence (ECL) is a widely applied technique for trace detection and analysis, but the stability of luminophores and external environmental factors strongly influence the analysis results. Herein, a low-potential ECL sensing platform based on enhanced nanomaterial catalysis for the traditional system luminol-H2O2 is proposed for the detection of neuron specific enolase (NSE). In this strategy, Au nanoparticles modified with three-dimensional graphitic phase carbon nitride (3DCNA) were used as a solid platform for antibodies (Ab2), which not only solved the problem of accumulation between traditional two-dimensional nanosheets but also had good biocompatibility, ensuring the accuracy of the analysis results. CoSn(OH)6, benefiting from its inherently higher catalytic activity and greater number of adsorption sites on perovskite hydroxide, can catalyze the oxidationreduction reaction of H2O2 to improve the ECL behavior of luminol and lower the applied voltage to reduce damage to biological activity. Owing to these exceptional properties, this proposed sandwich ECL immunosensor was explored for the primary diagnosis of SCLC by detecting NSE with a detection limit of 0.18 pg mL–1. It exhibited satisfactory linearity in the range of 0.0005 ng mL–1 to 100 ng mL–1 with favorable stability, excellent specificity, and good reproducibility. This study provides an important reference for low-potential ECL with promising application prospects in actual clinical analysis and detection.

Advances and Challenges in Nanomaterial-Based Electrochemical Immunosensors for Small Cell Lung Cancer Biomarker Neuron-Specific Enolase.

Early and rapid detection of neuron-specific enolase (NSE) is highly significant, as it is putative biomarker for small-cell lung cancer as well as COVID-19. Electrochemical techniques have attracted substantial attention for the early detection of cancer biomarkers due to the important properties of simplicity, high sensitivity, specificity, low cost, and point-of-care detection. This work reviews the clinically relevant labeled and label-free electrochemical immunosensors developed so far for the analysis of NSE. The prevailing role of nanostructured materials as electrode matrices is thoroughly discussed. Subsequently, the key performances of various immunoassays are critically evaluated in terms of limit of detection, linear ranges, and incubation time for clinical translation. Electrochemical techniques coupled with screen-printed electrodes developing market level commercialization of NSE sensors is also discussed. Finally, the review concludes with the current challenges associated with available methods and provides a future outlook toward commercialization opportunities for easy detection of NSE.

Polyacrylic acid/polyethylene glycol hybrid antifouling interface for photoelectrochemical immunosensing of NSE based on ZnO/CdSe.

In this paper, a novel photoelectrochemical (PEC) immunosensor based on ZnO/CdSe semiconductor composite material was constructed to detect neuron-specific enolase (NSE) in a super-sensitive and quantitative way. The antifouling interface composed of polyacrylic acid (PAA) and polyethylene glycol (PEG) can prevent non-specific proteins from adhering to the electrode surface. As an electron donor, ascorbic acid (AA) can increase the photocurrent's stability and intensity by clearing away photogenerated holes. Because of the specific recognition between antigen and antibody, the quantitative detection of NSE can be achieved. The PEC antifouling immunosensor based on ZnO/CdSe has a wide linear range (0.10pgmL-1-100ngmL-1) and a low detection limit (34fgmL-1), which has potential application in the clinical diagnosis of small cell lung cancer.

A split-type photoelectrochemical immunosensor based on a high-performance In2O3/BiVO4 photoelectrode modulated by a ZIF-8 protective layer

Herein, a split-type photoelectrochemical (PEC) immunosensor is designed to detect neuron-specific enolase (NSE), which is a tumor marker for small cell lung cancer present in nerve and neuroendocrine tissues. In this study, a heterogeneous In2O3/BiVO4 structure is developed with coral-like BiVO4 films adsorbed onto In2O3 based on simplified successive ionic layer adsorption and reaction (s-SILAR). Moreover, immune recognition occurs in a 96-well plate in the split-type PEC immunosensor, thus effectively avoiding interference with the recognition of biomolecules. However, the sensitivity of zeolitic imidazolate framework (ZIF)− 8 molecules to pH varies, and most of the degradation of ZIF-8 molecules can be achieved by a reaction at a pH of 5.5–6.5 for > 30 min. Therefore, SiO2-glucose oxidase is selected as a regulatory switch to act on ZIF-8 molecules by catalyzing the conversion of glucose to gluconic acid, whereas In2O3/BiVO4 is selected as the photoactive substrate and ZIF-8 protective layer as the signal switch. By constructing a split-type PEC immunosensor, gluconic acid of different concentrations is released in the 96-well plate through the change of NSE concentration to regulate the degradation of the ZIF-8 protective layer and achieve the sensitive detection of NSE. The constructed PEC sensor exhibits an excellent photocurrent response between 0.1 pg mL–1 and 100 ng mL–1, with a detection limit of 0.03 pg mL–1. Simultaneously, the accuracy, specificity, stability, and reproducibility of this split-type PEC sensing platform predict its promising application in the future in the field of biomolecules.

Direct detection of neuron-specific enolase using a spectrometer-free colorimetric plasmonic biosensor.

Sensitive detection of a tumor marker, neuron-specific enolase (NSE), was performed by a label-free direct immunoassay based on a colorimetric plasmonic biosensor. Reflective plasmonic colors of silver nanodome arrays provided a way for a sensitive refractive index sensor based on spectrometer-free colorimetric detection. The direct detection of NSE was demonstrated by a combination of a sensitive sensor substrate and image processing. The limit of detection (LOD) for NSE was determined to be 270 pM, which is lower than the clinical threshold value of NSE used for medical diagnostics of small-cell lung cancer. Since our substrate-based colorimetric plasmonic biosensor is compatible with smartphone detection, we believe that the presented biosensor will open up a way for biosensor technology for point-of-care testing as well as mobile health applications.

Electrochemiluminescence resonance energy transfer between a Ru-ZnMOF self-enhanced luminophore and a double quencher ZnONF@PDA to detect NSE.

The construction of advanced systems capable of accurately detecting neuron-specific enolase (NSE) is essential for rapidly diagnosing small-cell lung cancer. In this study, an electrochemiluminescence (ECL) resonance energy transfer immunosensor was proposed for the ultra-sensitive detection of NSE. The co-reactants C2O42- and Ru(bpy)32+ were integrated to form a self-enhanced ECL luminophore (Ru-ZnMOF) as the ECL donor. The abundant carboxyl functional groups of Ru-ZnMOF supported antibody 1 via an amidation reaction. Polydopamine-modified zinc dioxide nanoflowers, as ECL acceptors, inhibited Ru-ZnMOF ECL signaling. The linear range of NSE was 10 fg mL-1 to 100 ng mL-1 with a detection limit of 3.3 fg mL-1 (S/N = 3), which is suitably low for determining NSE in real samples.

Photoelectrochemical Immunosensor Based on a 1D Fe2O3/3D Cd-ZnIn2.2Sy Heterostructure as a Sensing Platform for Ultrasensitive Detection of Neuron-Specific Enolase.

Lung cancer is a high-mortality cancer related to the concentration of neuron-specific enolase (NSE). In this work, a sandwich-type photoelectrochemical (PEC) immunosensor was constructed for ultrasensitive detection of NSE, which is based on iron trioxide/indium zinc cadmium sulfide (Fe2O3/Cd-ZnIn2.2Sy) as a sensing platform and Ag-modified polyaniline (Ag@PANI) as a signal amplification label. The 1D Fe2O3 porous nanorods with a large specific surface area were synthesized by calcination of Fe-MIL-88A and etching of NaOH. To improve the photocurrent response, the 3D architecture Cd-ZnIn2.2Sy was combined with the 1D Fe2O3 porous nanorods to form a 1D Fe2O3/3D Cd-ZnIn2.2Sy heterostructure. Specifically, the Fe2O3/Cd-ZnIn2.2Sy heterostructure with a good energy level matching (the two can form a stepped energy level matching, which accelerates the transfer rate of electrons) can improve the separation efficiency of electron-hole pairs (e-/h+) under visible light irradiation, which enhances the photocurrent response. Ag@PANI has a strong electron transport capability and can be used as a secondary antibody marker for the signal amplification of the immunosensor. The sensor exhibits a good linear detection range of 100 fg/mL to 100 ng/mL with a low detection limit of 33.5 fg/mL. Moreover, the constructed sandwich-type PEC immunosensor shows good performance and possesses excellent specificity, selectivity, and stability over a period of 4 weeks for NSE detection. With these excellent properties, the immunosensor can be extended to analyze and diagnose other disease biomarkers.

Split-Type Photoelectrochemical/Visual Sensing Platform Based on SnO2/MgIn2S4/Zn0.1Cd0.9S Composites and Au@Fe3O4 Nanoparticles for Ultrasensitive Detection of Neuron Specific Enolase.

Herein, a novel dual mode detection system of split-type photoelectrochemical (PEC) and visual immunoassay was developed to detect neuron specific enolase (NSE), which achieved simultaneous and reliable NSE detection due to the completely different signal readouts and transduction mechanism. Specifically, specific reactions of antigens and antibodies were performed in 96-microwell plates. Gold nanoparticle (Au NP)-loaded Fe3O4 (Au@Fe3O4) NPs were used as secondary antibody markers and signal regulators, which could produce a blue-colored solution in the presence of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 because of its peroxidase-like activity. Therefore, the visual detection of NSE was realized, making the results more intuitive. Meanwhile, the above biological process could also be used as part of the split-type PEC sensing platform. Oxidized TMB and Fe3+ were consumptive agents of the electron donor, which both realized the double quenching of PEC signal generated by the SnO2/MgIn2S4/Zn0.1Cd0.9S composites. Owing to the waterfall band structure, SnO2/MgIn2S4/Zn0.1Cd0.9S composites partially absorb visible light and effectively inhibit the electron-hole recombination, thereby providing significantly enhanced and stable initial signal. On the basis of the multiple signal amplification strategy and the split-type mode, NSE could be sensitively detected with a low detection limit of 14.0 fg·mL-1 (S/N = 3) and a wide linear range from 50.0 fg·mL-1 to 50.0 ng·mL-1.

Ultrasensitive photoelectrochemical sensing platform for detection of neuron specific enolase based on inhibition effect of CoSnO3 nanobox toward SnO2/Mn0.05Cd0.95S composites

Herein, a novel photoelectrochemical (PEC) immunoassay was developed to detect Neuron specific enolase (NSE) based on the inhibition effect of CoSnO3 nanobox toward Mn0.05Cd0.95S sensitized stannic oxide (SnO2). Specifically, the SnO2/Mn0.05Cd0.95S composites with excellent photoelectric properties were employed as substrate materials, which could partially absorb visible-light and effectively inhibit the electron-hole recombination owing to the effect of heterostructure, therefore providing significantly enhanced and stable basal signal. Then, the CoSnO3 nanobox with excellent steric hindrance effect, uniform size and easy modification was used as labeled secondary antibody, which could obstruct the electrons transfer and further facilitate the decrease of photocurrent intensity to achieve the amplification of signal change value. The high sensitivity and good stability of the immunoassay derived from the enhancement of the original signal and the amplification of signal changes. Accordingly, the as-fabricated PEC immunosensor responded sensitively to NSE with a low detection limit of 0.15 pg mL−1 and a wide linear range from 0.50 pg mL−1 to 100 ng mL−1. Moreover, the immunosensor also presented good stability, excellent specificity and satisfactory reproducibility, which can provide a potential analytical strategy for NSE and other biomolecules, and provided guidance for the early diagnosis and clinical analysis of small-cell lung cancer (SCLC).