Single-cell and spatial transcriptomics reveal metastasis mechanism and microenvironment remodeling of lymph node in osteosarcoma.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignant bone tumor and is highly prone to metastasis. OS can metastasize to the lymph node (LN) through the lymphatics, and the metastasis of tumor cells reestablishes the immune landscape of the LN, which is conducive to the growth of tumor cells. However, the mechanism of LN metastasis of osteosarcoma and remodeling of the metastatic lymph node (MLN) microenvironment is not clear. METHODS: Single-cell RNA sequencing of 18 samples from paracancerous, primary tumor, and lymph nodes was performed. Then, new signaling axes closely related to metastasis were identified using bioinformatics, in vitro experiments, and immunohistochemistry. The mechanism of remodeling of the LN microenvironment in tumor cells was investigated by integrating single-cell and spatial transcriptomics. RESULTS: From 18 single-cell sequencing samples, we obtained 117,964 cells. The pseudotime analysis revealed that osteoblast(OB) cells may follow a differentiation path from paracancerous tissue (PC) → primary tumor (PT) → MLN or from PC → PT, during the process of LN metastasis. Next, in combination of bioinformatics, in vitro and in vivo experiments, and immunohistochemistry, we determined that ETS2/IBSP, a new signal axis, might promote LN metastasis. Finally, single-cell and spatial dissection uncovered that OS cells could reshape the microenvironment of LN by interacting with various cell components, such as myeloid, cancer-associated fibroblasts (CAFs), and NK/T cells. CONCLUSIONS: Collectively, our research revealed a new molecular mechanism of LN metastasis and clarified how OS cells influenced the LN microenvironment, which might provide new insight for blocking LN metastasis.

Real-world setting comparison of bridging therapy versus direct mechanical thrombectomy for acute ischemic stroke: A meta-analysis.

BACKGROUND AND PURPOSE: Intravenous Thrombolysis (IVT) prior to Mechanical Thrombectomy (MT) for Acute Ischaemic Stroke (AIS) due to Large-Vessel Occlusion (LVO) remains controversial. Therefore, the authors performed a meta-analysis of the available real-world evidence focusing on the efficacy and safety of Bridging Therapy (BT) compared with direct MT in patients with AIS due to LVO. METHODS: Four databases were searched until 01 February 2023. Retrospective and prospective studies from nationwide or health organization registry databases that compared the clinical outcomes of BT and direct MT were included. Odds Ratios (ORs) and 95 % Confidence Intervals (CIs) for efficacy and safety outcomes were pooled using a random-effects model. RESULTS: Of the 12 studies, 86,695 patients were included. In patients with AIS due to LVO, BT group was associated with higher odds of achieving excellent functional outcome (modified Rankin Scale score 0-1) at 90 days (OR = 1.48, 95 % CI 1.25-1.75), favorable discharge disposition (to the home with or without services) (OR = 1.33, 95 % CI 1.29-1.38), and decreased mortality at 90 days (OR = 0.62, 95 % CI 0.56-0.70), as compared with the direct MT group. In addition, the risk of symptomatic intracranial hemorrhage did not increase significantly in the BT group. CONCLUSION: The present meta-analysis indicates that BT was associated with favorable outcomes in patients with AIS due to LVO. These findings support the current practice in a real-world setting and strengthen their validity. For patients eligible for both IVT and MT, BT remains the standard treatment until more data are available.

Case Report: Early-Onset Charcot-Marie-Tooth 2N With Reversible White Matter Lesions Repeatedly Mimicked Stroke or Encephalitis.

Introduction: Charcot-Marie-Tooth (CMT) disease is a rare group of peripheral neuropathies with high clinical and genetic heterogeneity. CMT type 2N (CMT 2N) is a rare subtype of CMT with few clinical reports. The clinical presentation mimics that of other diseases, frequently leading to misdiagnoses. We present a case of CMT 2N with reversible white matter lesions (WMLs), which repeatedly mimicked stroke or encephalitis. We include a literature review to the improve management of this disease. Case Description: An 8-year-old boy was admitted to the hospital with slurred speech and limb weakness that had persisted for 1 day. Physical examination revealed lethargy, dysarthria, and a positive bilateral Babinski sign. Cerebrospinal fluid (CSF) analysis showed no abnormalities. Brain magnetic resonance imaging (MRI) revealed symmetrical abnormal signal areas in the paraventricular white matter and corpus callosum. The patient was suspected of having viral encephalitis and recovered rapidly after treatment.He was hospitalized 3 years later for limb weakness, barylalia, and facial paralysis persisting for 1 day. MRI showed an abnormal signal in the bilateral corona radiata. He was suspected of having a stroke or encephalitis. He was completely recovered after treatment.After a second 3-year span, he was admitted for another stroke-like episode. Physical examination revealed facial-lingual hemiparesis, mild atrophy of the left thenar muscle, decreased muscle strength in the extremities, and disappearance of the tendon reflex. MRI revealed more pronounced abnormal signals in the bilateral centrum semiovale and corpus callosum. Antibodies against autoimmune encephalitis were negative. A nerve conduction velocity (NCV) study showed motor and sensory four-limb nerve demyelination with axonal damage, most notably at the distal end. His symptoms were resolved after active treatment. A follow-up MRI showed the complete disappearance of the abnormal white matter signal. Whole exon sequencing showed a heterozygous mutation [c.2093C > T(p.Ser698Phe)] in the alanyl-tRNA synthetase 1 gene (AARS1). His mutation, clinical features, and electrophysiological testing led to a diagnosis of CMT 2N. Discussion: Early-Onset CMT 2N with reversible WMLs can often mimic stroke or encephalopathy. Affected individuals may show an atypical posterior reversible encephalopathy syndrome (PRES) on MRI. Careful family history assessment, physical examination, nerve conduction studies, MRIs, and genetic testing are essential for early diagnosis. Further studies are required to confirm these findings.

Case report: biotin-thiamine-responsive basal ganglia disease with severe subdural hematoma on magnetic resonance imaging.

Background: Biotin-thiamine-responsive basal ganglia disease (BTBGD) is a rare, treatable autosomal recessive neurometabolic disorder. This condition eventually leads to severe disability and death if not treated correctly. The clinical features of BTBGD, especially those with unusual complications, are not widely known by neurologists or pediatricians.Case presentation: A 4-month-old male infant was admitted to the hospital with a history of cough for the past 7 days and convulsions of 6 h duration. Physical examination showed confusion, bilateral pupillary light reflex delays, hypertonia of limbs, and brisk tendon reflexes of the limbs. Brain magnetic resonance imaging (MRI) showed multiple abnormal signals in the bilateral basal ganglia, lobes, corpus callosum, brainstem, and brain atrophy. However, his condition continued to worsen. Computed tomography performed 3 months later showed severe subdural hematoma and effusion. Subsequently, he underwent puncture drainage; however, his condition did not improve postoperatively. Repeated MRIs showed increasing subdural hematoma and effusion, and brain atrophy. The patient was diagnosed with BTBGD following whole-genome sequencing, which identified a novel compound heterozygous mutation of SLC19A3 gene. He was treated with biotin and thiamine, and the symptoms gradually improved. Subsequent MRIs showed a decrease in the subdural hematoma and effusion and partial improvement in brain atrophy.Conclusion: To the best of our knowledge, this is the first reported case of BTBGD, complicated by severe subdural hematoma. These observations extend our understanding of the clinical features, neuroimaging spectrum, and gene mutation spectrum of BTBGD. The phenotypic spectrum and pathophysiology of BTBGD are not completely understood and need to be studied further.

Endovascular treatment for wake-up stroke and daytime unwitnessed stroke: A meta-analysis.

BACKGROUND: Evidence from sources outside the typical clinical research setting, such as a real-world setting, may complement evidence from randomised controlled trials (RCTs). The aim of the present study was to carry out a meta-analysis of available real-world evidence that focused on the efficacy and safety of endovascular treatment in patients with wake-up stroke (WUS) or daytime unwitnessed stroke (DUS) compared to that in patients treated ≤ 6 h after the onset of an ischemic stroke. METHODS: Data mining was conducted on 1 May 2021 from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials Cochrane Library. The study reviewed all published that assessed the effect of endovascular treatment in WUS and DUS compared to that received by patients with ischemic stroke. Relevant data were extracted and the narrative was reviewed and analysed. The results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). FINDINGS: The meta-analysis showed no significant differences between the two groups in the rates of functional independence (OR, 0.81; 95% CI, 0.65-1.02; P = 0.07), symptomatic intracerebral haemorrhage (OR, 0.86; 95% CI, 0.57-1.30; P = 0.470), and all-cause mortality (OR, 0.92; 95% CI, 0.73-1.16; P = 0.50). There was also no heterogeneity between the trials. CONCLUSION: The pooled analysis provided evidence to support the use of endovascular treatment in WUS and DUS with favourable perfusion imaging. The meta-analysis confirmed the main findings of RCTs of endovascular treatment in WUS and DUS in a real-world setting and therefore strengthens the validity of this treatment strategy.

Characterization and Genetic Diversity of Pseudomonas syringae pv. syringae Isolates Associated with Rice Bacterial Leaf Spot in Heilongjiang, China.

In China, rice is one of the most important cereal crops. Rice bacterial brown leaf spot caused by P. s. pv. syringae is among the most damaging rice diseases in the Heilongjiang Province of China and results in substantial yield losses. In this study, a comprehensive analysis of the pathogen, population structure, and genetic diversity within the species was performed. For this purpose, 176 bacterial isolates of P. s. pv. syringae collected from 15 locations were characterized by using biochemical tests such as the LOPAT test, and genetic characterizations such as multilocus sequence analysis (MLSA) and repetitive PCR, using BOX, REP and ERIC primers. Biochemical testing and detection of syrB genes confirm the presence of P. s. pv. syringae, genetic characterization by MLSA and genetic fingerprinting by repetitive PCR confirmed that high genetic heterogeneity exists in the P. s. pv. syringae isolates, and clustering of the tested isolates and reference strains are related with the same genomospecies 1. This work contributes to the physiological classification of the P. s. pv. syringae isolated from Heilongjiang Province, China, and the results present new data concerning the phylogeny and genetic diversity. This type of study about P. s. pv. syringae has been not reported from this region until now.

Cascades between miRNAs, lncRNAs and the NF-κB signaling pathway in gastric cancer (Review).

Gastric cancer is a common digestive tract malignancy that is mainly treated with surgery combined with perioperative adjuvant chemoradiotherapy and biological targeted therapy. However, the diagnosis rate of early gastric cancer is low and both postoperative recurrence and distant metastasis are thorny problems. Therefore, it is essential to study the pathogenesis of gastric cancer and search for more effective means of treatment. The nuclear factor-κB (NF-κB) signaling pathway has an important role in the occurrence and development of gastric cancer and recent studies have revealed that microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are able to regulate this pathway through a variety of mechanisms. Understanding these interrelated molecular mechanisms is helpful in guiding improvements in gastric cancer treatment. In the present review, the functional associations between miRNAs, lncRNAs and the NF-κB signaling pathway in the occurrence, development and prognosis of gastric cancer were discussed. It was concluded that miRNAs and lncRNAs have complex relations with the NF-κB signaling pathway in gastric cancer. miRNAs/target genes/NF-κB/target proteins, signaling molecules/NF-κB/miRNAs/target genes, lncRNAs/miRNAs/NF-κB/genes or mRNAs, lncRNAs/target genes/NF-Κb/target proteins, and lncRNAs/NF-κB/target proteins cascades are all important factors in the occurrence and development of gastric cancer.

14-3-3 σ: A potential biomolecule for cancer therapy.

As more studies have focused on the function of 14-3-3 proteins, their role in tumor progression has gradually improved. In the 14-3-3 protein family, 14-3-3σ is the protein that is most associated with tumor occurrence and development. In some malignancies, 14-3-3σ acts as a tumor suppressor via p53 and tumor suppressor genes. In most tumors, 14-3-3σ overexpression increases resistance to chemotherapy and radiotherapy and mediates the G2-M checkpoint after DNA damage. Although 14-3-3σ overexpression has been closely associated with poorer prognosis in pancreatic, gastric and colorectal cancer, its role in gallbladder and nasopharyngeal cancer remains less clear. As such, the function of 14-3-3σ in specific cancer types needs to be further clarified. It has been hypothesized that a role may be related to its molecular chaperone function combined with various protein ligands. In this review, we examine the role of 14-3-3σ in tumor development and drug resistance. We discuss the potential of targeting 14-3-3σ regulators in cancer therapy and treatment.

Pre etched Ag nanocluster as SERS substrate for the rapid quantification of AFB1 in peanut oil via DFT coupled multivariate calibration.

The current study extends the use of surface-enhanced Raman spectroscopy (SERS) combined with density functional theory (DFT) and multivariate calibration towards the rapid quantification of aflatoxin B1 (AFB1) in peanut oil samples. It reports the design of pre etched Ag nanocluster as an active SERS substrate for quantifying AFB1, after being impregnated on its surface. The SERS spectra of AFB1@pre etched Ag nanocluster was recorded and its respective theoretical spectrum was calculated by density functional theory (DFT) to assign the characteristic peaks. The baseline drift and rotation effects were masked by the first-order derivative preprocessing method followed by multivariate calibration. The BP-AdaBoost model exhibited optimum prediction (Rp = 0.9283 and 0.9332) ability over the concentration range 5-100 and 100-1000 ngmL-1, respectively. The limit of detection calculated was 5.0 ngmL-1 and the obtained recoveries were in the range from 90.4% to 113.1% in spiked peanut oil samples. Additionally, precision analysis revealed an RSD ca. 5%, suggesting the applicability of the pre etched Ag nanocluster SERS substrate towards AFB1 detection. Thus, the proposed SERS platform exploiting DFT and BP-AdaBoost model was found reproducible for the quantification of AFB1 in peanut oil.

Circular RNAs in nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a geographical distributed epithelial tumor of head and neck, which is prevalent in east Africa and Asia, especially southern China. Moreover, NPC has an unfavorable clinical effect and is prone to metastasis at an advanced stage. Although the recovery rate of patients has been improved due to concurrent chemoradiotherapy, poor curative effects and low overall survival remain key issues. The precise mechanisms and pivotal regulators of NPC remain still unclear. To improve the therapeutic efficacy, we focused on related-NPC circular RNAs (circRNAs). CircRNAs are a unique type of endogenous non-coding RNAs (ncRNAs) with a covalent closed-loop structure. Their expression is rich, stable and conservative. Different circRNA have specific tissue and developmental stages and can be detected in body fluids. In addition, circRNAs are involved in multiple pathological processes, especially in cancers. In recent years, using high-throughput indicator technology and bioinformatics technology, a large number of circRNAs have been identified in NPC cells and verified to have biological functions and mechanisms of action. This article aims to provide a retrospective review of the latest research on the proliferation and migration of related-NPC circRNA. Specifically, we focused on the roles and mechanisms of circRNAs in the development and progression of NPC. CONCLUSION: CircRNA can act as an oncogene or tumor suppressor gene and participate in NPC progression (e.g., proliferation, apoptosis, migration, and invasion). In short, circRNAs have potential as biomarkers for the diagnosis, prognosis and treatment of NPC.

Radio-Susceptibility of Nasopharyngeal Carcinoma: Focus on Epstein- Barr Virus, MicroRNAs, Long Non-Coding RNAs and Circular RNAs.

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. As a neoplastic disorder, NPC is a highly malignant squamous cell carcinoma that is derived from the nasopharyngeal epithelium. NPC is radiosensitive; radiotherapy or radiotherapy combining with chemotherapy are the main treatment strategies. However, both modalities are usually accompanied by complications and acquired resistance to radiotherapy is a significant impediment to effective NPC therapy. Therefore, there is an urgent need to discover effective radio-sensitization and radio-resistance biomarkers for NPC. Recent studies have shown that Epstein-Barr virus (EBV)-encoded products, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which share several common signaling pathways, can function in radio-related NPC cells or tissues. Understanding these interconnected regulatory networks will reveal the details of NPC radiation sensitivity and resistance. In this review, we discuss and summarize the specific molecular mechanisms of NPC radio-sensitization and radio-resistance, focusing on EBV-encoded products, miRNAs, lncRNAs and circRNAs. This will provide a foundation for the discovery of more accurate, effective and specific markers related to NPC radiotherapy. EBVencoded products, miRNAs, lncRNAs and circRNAs have emerged as crucial molecules mediating the radio-susceptibility of NPC. This understanding will improve the clinical application of markers and inform the development of novel therapeutics for NPC.

Vortioxetine treatment for generalised anxiety disorder: a meta-analysis of anxiety, quality of life and safety outcomes.

OBJECTIVES: The aim of this study was to investigate the efficacy, tolerability, safety, and impact on quality of life (QoL) and functional status of vortioxetine treatment for patients with generalised anxiety disorder (GAD) by performing a meta-analysis of randomised controlled trials (RCTs). DESIGN: Systematic review and meta-analysis. DATA SOURCES: Data mining was conducted in January 2019 across PubMed, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials Cochrane Library, Web of science and ClinicalTrials.gov. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: All published RCTs, which assessed the effect of vortioxetine treatment for patients with GAD when compared with a placebo group, were included. DATA EXTRACTION AND SYNTHESIS: Relevant data were extracted and synthesised narratively. Results were expressed as standardised mean differences or ORs with 95% CIs. RESULTS: Our meta-analysis showed that multiple doses (2.5, 5 and 10 mg/day) of vortioxetine did not significantly improve the response rates, compared with placebo (OR 1.16, 95% CI 0.84 to 1.60, p=0.38; OR 1.41, 95% CI 0.82 to 2.41, p=0.21; and OR 1.05, 95% CI 0.76 to 1.46, p=0.75). Moreover, there was no statistically significant difference regarding the remission rates, discontinuation for any reason rates, discontinuation due to adverse events rates, Short-Form 36 Health Survey scores or Sheehan Disability Scale scores between administration of multiple doses (2.5, 5 and 10 mg/day) of vortioxetine and placebo. CONCLUSIONS: Although our results suggest that vortioxetine did not improve the GAD symptoms, QoL and functional status impairment of patients with GAD, it was safe and well tolerated. Clinicians should interpret and translate our data with caution, as the meta-analysis was based on a limited number of RCTs.

rGO-NS SERS-based coupled chemometric prediction of acetamiprid residue in green tea.

Pesticide residue in food is of grave concern in recent years. In this paper, a rapid, sensitive, SERS (Surface-enhanced Raman scattering) active reduced-graphene-oxide-gold-nano-star (rGO-NS) nano-composite nanosensor was developed for the detection of acetamiprid (AC) residue in green tea. Different concentrations of AC combined with rGO-NS nano-composite electro-statically, yielded a strong SERS signal linearly with increasing concentration of AC ranging from 1.0 × 10-4 to 1.0 × 103 µg/mL indicating the potential of rGO-NS nano-composite to detect AC in green tea. Genetic algorithm-partial least squares regression (GA-PLS) algorithm was used to develop a quantitative model for AC residue prediction. The GA-PLS model achieved a correlation coefficient (Rc) of 0.9772 and recovery of the real sample of 97.06%-115.88% and RSD of 5.98% using the developed method. The overall results demonstrated that Raman spectroscopy combined with SERS active rGO-NS nano-composite could be utilized to determine AC residue in green tea to achieve quality and safety.

Real-World Outcomes of Acute Ischemic Stroke Treatment with Intravenous Thrombolysis: A Systematic Review and Meta-Analysis.

BACKGROUND: Evidence from outside the typical clinical research setting, such as the real-world setting, complements evidence coming from randomized controlled trials. The purpose of this study was to evaluate all available evidence from the real-world observational trials about long-term outcomes of treatment with intravenous (IV) recombinant tissue-type plasminogen activator (rt-PA) compared with not treated with IV rt-PA (non-rt-PA) in patients with acute ischemic stroke. METHODS: We searched PubMed and Embase until March 1, 2018 for observational studies reporting matched or adjusted results comparing IV rt-PA versus non-rt-PA in patients with acute ischemic stroke. Outcomes assessed included all-cause mortality, hospital readmission rates, and independence rates. Hazard ratios with 95% confidence intervals were used as a measure of comparing between patients treated with IV rt-PA and non-rt-PA. RESULTS: Six observational trials with 16,399 participants were identified. The use of IV rt-PA in acute ischemic stroke patients was associated with a lower risk of mortality (hazard ratio .61; 95% confidence interval, .52-.70; P < .00001), and there was no heterogeneity across trials. There was no evidence of an effect on hospital readmission rates and independence rates. CONCLUSIONS: IV rt-PA is associated with reduced long-term mortality in acute ischemic stroke patients.

Effectiveness of high-frequency repetitive transcranial magnetic stimulation in patients with depression and Parkinson's disease: a meta-analysis of randomized, controlled clinical trials.

AIM: This meta-analysis aimed to assess the effect of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) for the treatment of depression in patients with Parkinson's disease (PD). METHODS: The design was a meta-analysis of randomized controlled trials (RCTs). The participants were patients with PD who suffered from depression. The interventions were HF-rTMS alone or in combination with other treatments compared with sham-rTMS, placebo, and anti-depressant treatments. The primary outcome measure was changes in depressive symptoms, defined as the mean change in the total depression score. The secondary outcome was changes in motor symptoms, defined by Unified Parkinson's Disease Rating Scale part III scores, and the acceptability, defined as the risk of all-cause discontinuation. These were expressed as mean differences (MDs), standardized mean differences (SMDs), or risk ratios (RRs) with 95% confidence intervals (CIs). RESULTS: We identified nine suitable trials, with data from 332 participants. For the patients with depression in PD, HF-rTMS was not better than sham-rTMS (SMD =-0.33, 95% CI -0.83 to 0.17) or selective serotonin re-uptake inhibitors (SSRIs) (SMD =0.07, 95% CI -0.52 to 0.18) for the treatment of depressive symptoms. However, the motor benefits after treatment with HF-rTMS might be better than sham-rTMS (MD =-2.80, 95% CI -5.45 to -0.15) and SSRIs (MD =-2.70, 95% CI -4.51 to -0.90). CONCLUSION: This meta-analysis provides some evidence that in patients with PD with depression, HF-rTMS may lead to improvement in motor function but not in depression compared with sham-rTMS or SSRIs.

Near infrared system coupled chemometric algorithms for enumeration of total fungi count in cocoa beans neat solution.

Total fungi count (TFC) is a quality indicator of cocoa beans when unmonitored leads to quality and safety problems. Fourier transform near infrared spectroscopy (FT-NIRS) combined with chemometric algorithms like partial least square (PLS); synergy interval-PLS (Si-PLS); synergy interval-genetic algorithm-PLS (Si-GAPLS); Ant colony optimization - PLS (ACO-PLS) and competitive-adaptive reweighted sampling-PLS (CARS-PLS) was employed to predict TFC in cocoa beans neat solution. Model results were evaluated using the correlation coefficients of the prediction (Rp) and calibration (Rc); root mean square error of prediction (RMSEP), and the ratio of sample standard deviation to RMSEP (RPD). The developed models performance yielded 0.951≤Rp≤0.975; and 3.15≤RPD≤4.32. The models' prediction stability improved in the order of PLS

A large Raman scattering cross-section molecular embedded SERS aptasensor for ultrasensitive Aflatoxin B1 detection using CS-Fe3O4 for signal enrichment.

With growing concern on oil safety problems, developing a simple and sensitive method to detect Aflatoxin B1 (AFB1), a common mycotoxin in peanut oil, is very necessary. In this study, Surface-enhanced Raman Scattering (SERS) aptasensor was developed for ultrasensitive AFB1 detection using the amino-terminal AFB1 aptamer (NH2-DNA1); and thiol-terminal AFB1 complementary aptamer (SH-DNA2) conjugated magnetic-beads (CS-Fe3O4) as enrichment nanoprobe and AuNR@DNTB@Ag nanorods (ADANRs) as reporter nanoprobe respectively. 5,5'-Dithiobis(2-nitrobenzoicacid) (DNTB) with large Raman scattering cross-section and no fluorescence interference was embedded in Au and Ag core/shell nanorods as Raman reporter molecules. CS-Fe3O4 possessed excellent biocompatibility and superparamagnetism for rapid signal enrichment. Therefore, NH2-DNA1-CS-Fe3O4 and SH-DNA2-ADANRs were fabricated via the hybrid reaction between aptamers and complementary aptamers. When there is AFB1, AFB1 would competitively combine with the NH2-DNA1-CS-Fe3O4 inducing the dissociation of SH-DNA2-ADANRs from CS-Fe3O4 and further decreasing the SERS signal. Based on this developed SERS aptasensor, a low limit of 0.0036ng/mL and an effective linear detection range from 0.01 to 100ng/mL with the correlation coefficient up to 0.986 for AFB1 detection were obtained. Moreover, the specificity of this SERS aptasensor was demonstrated by detecting other two mycotoxins and its accuracy for AFB1 detection in real peanut oil was further confirmed by standard addition recovery test.

A universal SERS aptasensor based on DTNB labeled GNTs/Ag core-shell nanotriangle and CS-Fe3O4 magnetic-bead trace detection of Aflatoxin B1.

A novel universal Surface-enhanced Raman Spectroscopy (SERS) based aptasensor platform for the trace detection of Aflatoxin B1 (AFB1), a common food contaminating mycotoxin, has been constructed, with the aid of the specific interaction between AFB1 and aptamers. The amino-terminal aptamer conjugated magnetic-bead (CS-Fe3O4) and the gold nanotriangles (GNTs)-DTNB@Ag-DTNB nanotriangles (GDADNTs) were used as the capturer and the reporter of AFB1, respectively. Under the optimized assay condition, the platform shows a distinguished sensitivity with the LOD as low as 0.54 pg/mL and the linear range from 0.001 to 10 ng/mL, a high stability of the SERS substrate activity remained three months at least, a decent reproducibility with RSD of ca. 5%, and a good selectivity to the general coexisted interferences. The distinguished sensitivity and selectivity for trace AFB1 detection has been achieved mainly due to the strong Raman enhancement effect of GNTs as the kernel for GDADNTs from the double-layer of the reporter molecules, the specificity of aptamer and superparamagnetic CS-Fe3O4 respectively. Furthermore, the proposed SERS aptasensor is universal to other trace molecules detection with the specific aptamers.