The self-powered electrochemical sensor has gained big achievements in energy and devices, but it is challenging in analytical application owing to its low energy conversion efficiency and limited ...selectivity caused by the plentiful interference in actual samples. Herein, a new self-powered biosensor was constructed by the integration of a photocatalytic fuel cell (PFC) with a molecular imprinting polymer (MIP) to achieve sensitive and specific detection of aflatoxin B1 (AFB1). Compared with other fuel cells, the PFC owns the advantages of low cost, high energy, good stability, and friendly environment by using light as the excitation source. MoS2–Ti3C2T x MXene (MoS2–MX) served as the photoanode material for the first time by forming a heterojunction structure, which can enhance the photocurrent by about 3-fold and greatly improve the photoelectric conversion efficiency. Aiming at the poor selectivity of the self-powered sensor, the MIP was introduced to achieve the specific capture and separation of targets without sample pretreatment. Using the MIP and PFC as recognition and signal conversion elements, respectively, the proposed self-powered biosensor showed a wide dynamic range of 0.01–1000 ng/mL with a detection limit of 0.73 pg/mL, which opened opportunities to design more novel self-powered biosensors and promoted its application in food safety and environmental monitoring.
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IJS, KILJ, NUK, PNG, UL, UM
Nitromethane (CH3NO2) is an important organic chemical raw material with a wide variety of applications as well as one of the most common pollutants. Therefore it is pretty important to establish a ...simple and sensitive detection method for CH3NO2. In our study, a novel amperometric biosensor for nitromethane (CH3NO2) based on immobilization of electrochemically-reduced graphene oxide (rGO), chitosan (CS) and hemoglobin (Hb) on a glassy carbon electrode (GCE) was constructed. Scanning electron microscopy, infrared spectroscopy and electrochemical methods were used to characterize the Hb-CS/rGO-CS composite film. The effects of scan rate and pH of phosphate buffer on the biosensor have been studied in detail and optimized. Due to the graphene and chitosan nanocomposite, the developed biosensor demonstrating direct electrochemistry with faster electron-transfer rate (6.48s−1) and excellent catalytic activity towards CH3NO2. Under optimal conditions, the proposed biosensor exhibited fast amperometric response (<5s) to CH3NO2 with a wide linear range of 5μM~1.46mM (R=0.999) and a low detection limit of 1.5μM (S/N=3). In addition, the biosensor had high selectivity, reproducibility and stability, providing the possibility for monitoring CH3NO2 in complex real samples.
•Graphene was produced by electrochemical reduction, which is green and efficient.•A biosensor based on electrochemically-reduced GO, CS and Hb was constructed.•The biosensor had a wide linear range of and a low detection limit for CH3NO2 detection.•The biosensor has been applied in real samples, with high selectivity and stability.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this work, an innovative aptasensor based on electrochemiluminescence resonance energy transfer (ECL-RET) from CdTe quantum dots (QDs) to a cyanine dye (Cy5) fluorophore for the determination of ...Ochratoxin A (OTA) was fabricated. A strong cathodic ECL emission was obtained by the CdTe QDs modified glassy carbon electrode (GCE). After the immobilization with the capture DNA (cDNA) and the sequential hybridization with the probe DNA-modified Cy5 (pDNA, the aptamer of OTA), the ECL signal enhanced obviously through the ECL-RET. Meanwhile, the spectrum- and distance-related ECL enhancement effect was investigated. When the target OTA was in the presence, the pDNA-Cy5 molecules were released from the electrode surface owing to the specific interaction between OTA and aptamer, resulting in an evident decrease of ECL signal. Under optimal conditions, the developed aptasensor displayed the linear response toward OTA in the wide range of 0.0005–50 ng/mL with a low detection limit of 0.17 pg/mL. With the excellent selectivity, stability and repeatability, the strategy provided an efficient and universal method for the sensitive detection of target in practical application.
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•A simple and convenient aptasensor for OTA was prepared.•The ECL-RET aptasensor based on CdTe QDs and Cy5 has high sensitivity.•This sensor has a good specificity since the great affinity of aptamer to target.•The aptasensor could be applied to detect OTA in corn.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A novel electrochemical aptamer biosensor was designed based on the signal amplification of gold nanoparticles (AuNPs) for the detection of a tumor biomarker, carcinoembryonic antigen (CEA). The ...electrochemical biosensor was constructed by sandwiching the CEA between an Au electrode modified with thiol-terminated CEA aptamer-1 (Apt1) and the AuNPs with thiol-terminated CEA aptamer-2 (Apt2) and 6-ferrocenyl hexanethiol (Fc). Amperometric detection of Fc by differential pulse voltammetry (DPV) on the electrochemical biosensor was used to quantify the concentration of CEA. The biosensor provided a linear range from 1 to 200ng/mL for CEA with a detection limit of 0.5ng/mL. Its performance was successfully evaluated with human serum spiked with CEA, indicating that the aptasensor has great potential for practical application. In addition, the electrochemical biosensor exhibited excellent selectivity responses and good stability toward the target analyte.
•A novel electrochemical aptasensor for the determination of CEA was developed.•Fc capped AuNPs–Apt2 conjugates were prepared for the signal amplification.•The electrochemical aptasensor showed a low background signal.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Programmed cell death protein 1 (PD-1) is one of the coinhibitory checkpoints upon T cell activation, the abnormal expression of which severely threatens host immune modulatation for chronic ...infection. Thus, fast and sensitive monitoring of PD-1 is of vital importance for early diagnosis and cancer treatment. The current detection methods largely based on enzyme-linked immunosorbent assay (ELISA) require time-consuming incubation and complicated washing steps. Herein, we designed a simple and portable nanofiber paper (NFP)-based fluorescence “off-on” immunosensor for PD-1 rapid determination. Molybdenum disulfide (MoS2) nanosheets modified NFP (MoS2–NFP) was employed for adsorbing and immobilizing CdSe/ZnS quantum dots-antibody (QDs-Ab) complex to construct a ready-to-use fluorescent immunosensor. The fluorescent signal of QDs-Ab was initially quenched by MoS2 under the Förster resonance energy transfer (FRET) effect. When the PD-1 target was specifically captured onto NFP by immunization, the QDs-Ab-PD-1 complex was promptly desorbed from the MoS2–NFP surface, resulting in FRET impediment and fluorescence recovery. As an alternative quenching agent, graphene oxide (GO) served as a contrast to investigate NFP-based sensing performance. Owing to superior quenching and desorption efficiency, the MoS2–NFP-based fluorescence immunosensor exhibited nearly 2-fold lower detection limit (85.5 pg/mL) than GO–NFP-based sensor (151 pg/mL) for PD-1 monitoring. Excellent selectivity and satisfactory recovery in PD-1 mouse cell culture supernatant samples were confirmed as well. In addition, the comparable detectability of the MoS2–NFP-based immunosensor was accurately evaluated by a standard PD-1 mouse ELISA kit. This study displayed a simple, rapid, low-cost, and portable point-of-care PD-1 assay, indicating its broad application prospect toward clinical diagnoses.
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IJS, KILJ, NUK, PNG, UL, UM
FGFR gene aberrations are associated with tumor growth and survival. We explored the role of FGFR2 amplification in gastric cancer and the therapeutic potential of AZD4547, a potent and selective ...ATP-competitive receptor tyrosine kinase inhibitor of fibroblast growth factor receptor (FGFR)1-3, in patients with FGFR2-amplified gastric cancer.
Array-comparative genomic hybridization and FISH were used to identify FGFR2 amplification in gastric cancer patient tumor samples. The effects of FGFR2 modulation were investigated in gastric cancer cells with FGFR2 amplification and in patient-derived gastric cancer xenograft (PDGCX) models using two approaches: inhibition with AZD4547 and short hairpin RNA (shRNA) knockdown of FGFR2.
Amplification of the FGFR2 gene was identified in a subset of Chinese and Caucasian patients with gastric cancer. Gastric cancer cell lines SNU-16 and KATOIII, carrying the amplified FGFR2 gene, were extremely sensitive to AZD4547 in vitro with GI50 values of 3 and 5 nmol/L, respectively. AZD4547 effectively inhibited phosphorylation of FGFR2 and its downstream signaling molecules and induced apoptosis in SNU-16 cells. Furthermore, inhibition of FGFR2 signaling by AZD4547 resulted in significant dose-dependent tumor growth inhibition in FGFR2-amplified xenograft (SNU-16) and PDGCX models (SGC083) but not in nonamplified models. shRNA knockdown of FGFR2 similarly inhibited tumor growth in vitro and in vivo. Finally, compared with monotherapy, we showed enhancement of in vivo antitumor efficacy using AZD4547 in combination with chemotherapeutic agents.
FGFR2 pathway activation is required for driving growth and survival of gastric cancer carrying FGFR2 gene amplification both in vitro and in vivo. Our data support therapeutic intervention with FGFR inhibitors, such as AZD4547, in patients with gastric cancer carrying FGFR2 gene amplification.
The outbreak of H9N2 avian influenza virus (H9N2 AIV) brings high mortality and huge economic losses every year. Sensitive and reliable detection methods are essential to timely diagnosis and ...treatment. Herein, a dual-modality immunoassay is proposed for H9N2 AIV detection by employing fluorescent-magnetic-catalytic nanospheres (FMCNs) as labels and alkaline phosphatase (ALP)-induced metallization as a signal amplification strategy. The excellent magnetic properties of FMCNs endow the assay a potential application in complex samples. Also, the excellent fluorescence properties of FMCNs enable fluorescence modality readout. The antibodies on the FMCN surface can achieve efficient capture and separation of targets. Amplified electrochemical modality readout can be obtained through ALP-catalyzed silver deposition. Dual-modality immunoassay combined the advantages of electrochemical assay with fluorescence assay and provides accurate detection results to meet different testing needs. With two quantitative analysis forms, H9N2 AIV can be detected by electrochemical signals with a quantitation range of 0.1 to 1000 ng/mL and a detection limit of 10 pg/mL. The linear range is 300 to 1000 ng/mL with a detection limit of 69.8 ng/mL by the fluorescence signal readout. Moreover, the specificity, anti-interference ability, accuracy, and diversity of the proposal have unlimited potential for early diagnosis of suspect infections.
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A novel platform based on a hairpin oligonucleotide (HO) switch, gold nanoparticles (AuNPs), and enzyme signal amplification for the ultrasensitive detection of mucin 1 protein (MUC1) was developed ...in this assay. This HO aptamers and horseradish peroxidase (HRP) were immobilised on the AuNPs to yield HO-AuNP-HRP conjugates. AuNPs were used as labels and bridges between the HO and HRP. HRP was also used as label for catalysing the oxidation of o-phenylenediamine by H2O2. The reaction product was 2,3-diaminophenazine (DAP), which was reduced and could be detected at surface of modified electrode. The reduction signal of DAP was used as a probe for the sensitive detection. After the recognition between oligonucleotide and MUC1, biotin was exposed. Biotin, along with the conjugate, was captured by streptavidin onto the surface of modified electrode. Therefore, the detection of target MUC1 which was a membrane-associated glycoprotein of the mucin family could be sensitively transduced via detection of the electrochemical reduction signal of DAP. Compared to other aptasensors, this biosensor has a good linear correlation ranges from 8.8 nM to 353.3 nM and a lower detection limit of 2.2 nM for MUC1. The proposed method provided a new electrochemical approach for the detection of MUC1.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
The purpose of our study was to evaluate the effect of surgery on the survival and prognosis of patients with multifocal intrahepatic cholangiocarcinoma (ICCA). Patients with multifocal ICCA ...were selected from the SEER (Surveillance, Epidemiology, and End Results) database between 2010 and 2016. Kaplan–Meier analyses and log-rank tests were used to evaluate the difference in survival between the surgery group and the non-surgery group. We applied the Cox proportional hazards regression model to identify prognostic factors of overall survival (OS) and cancer-specific survival (CSS). In total, 580 patients were enrolled in our study, including 151 patients who underwent surgery and 429 patients who did not. The median survival time of surgical patients was longer than non-surgical patients (OS: 25 months vs. 8 months, p < 0.001; CSS: 40 months vs. 25 months, p < 0.001). Similarly, the 5-year survival rate in the surgery group was significantly higher than those in the non-surgery group (5-year OS rate: 12.91% vs. 0%; p < 0.001; 5-year CSS rate:26.91% vs. 0%; p < 0.001). Multivariate Cox analysis showed that the OS (HR:0.299, 95% CI: 0.229–0.390, p < 0.001) and CSS (HR:0.305, 95% CI:0.222–0.419, p < 0.001) of patients undergoing surgical resection were significantly improved. Meanwhile, after propensity score matching (PSM) of the original data, we come to the same conclusion.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Electrochemiluminescence (ECL) detection has attracted increasing attention as a promising analytical approach. A considerable number of studies showed that ECL intensity can be definitely improved ...by resonance energy transfer (RET), while the RET efficiency is strongly dependent on the distance between exited donors and acceptors. Herein we disclose for the first time a highly enhanced RET strategy to promote the energy transfer efficiency by coencapsulating the donor (Ru(bpy)32+)/acceptor (CdTe quantum dots, CdTe QDs) pairs into a silica nanosphere. Plenty of Ru(bpy)32+ and CdTe QDs closely packed inside a single nanosphere greatly shortens the electron-transfer path and increases the RET probability, therefore significantly enhancing the luminous efficiency. Further combining with molecularly imprinting technique, we develop a novel ECL sensor for ultrasensitive and highly selective detection of target molecules. Proof of concept experiments showed that extremely low detection limits of subfg/mL (S/N = 3) with broad linear ranges (fg/mL to ng/mL) could be obtained for detection of two kinds of mycotoxins (α-ergocryptine and ochratoxin A) that are recognized as potential health hazards at very low concentrations. This strategy combining enhanced RET system and molecularly imprinting technique, represents a versatile ECL platform toward low-cost, rapid, ultrasensitive, and highly selective detection of target molecules in diverse applications.
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IJS, KILJ, NUK, PNG, UL, UM
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