UIO66 low background signal and fluorescence synergism strategy for highly sensitive detection of Salmonella typhimurium.

Successful construction of a detection method for Salmonella typhimurium (S. typhimurium) based on the synergy of hybridization chain reaction (HCR) and fluorescence was realized in this paper. First, the aptamer modified with the quenching group Black Hole Quencher-1 acid (BHQ1) was immobilized on the magnetic beads in combination with the complementary chain of the aptamer modified with 6-carboxyfluorescein (6-FAM). Second, S. typhimurium and cDNA-6-FAM immobilized on magnetic beads competitively bound to the aptamer. Finally, the cDNA-6-FAM was released after magnetic separation acted as a promoter to trigger HCR amplification when the target presented. The fluorescence signal could be significantly improved by the combination of green SYBR Green I (SGI) and HCR long double-stranded DNA and the fluorescent synergy of 6-FAM and SGI. Because of the separation of target and its aptamer, the trigger strand was abstracted by magnetic separation. There was no HCR to generate long double-stranded DNA, and the fluorescence of excess hairpin/SGI could be adsorbed through UIO66 so that only a very low background signal was detected. This fluorescent sensor was capable of monitoring S. typhimurium in the range of 10-3.2 × 107 CFU mL-1 with a limit of detection as low as 1.5 CFU mL-1. Because of the excellent properties of the aptasensor and the validity of SGI fluorescence synergy, this HCR enzyme-free amplification strategy could be generalized to other areas.

Umeclidinium plus vilanterol versus fluticasone propionate plus salmeterol for chronic obstructive pulmonary disease: a meta-analysis of randomized, controlled trials.

PURPOSE: Umeclidinium plus vilanterol (UMEC/VI) is an inhaled long-acting muscarinic antagonist/long-acting beta2-agonist (LAMA/LABA), recently approved as once-daily maintenance therapy for chronic obstructive pulmonary disease (COPD). This meta-analysis aims to assess the efficacy and safety of UMEC/VI compared with fluticasone propionate plus salmeterol (FP/SAL). METHODS: A systematic search was conducted by a trained medical research librarian across MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese Biomedical Literature Database (CBM) for randomized controlled trials comparing UMEC/VI with FP/SAL in COPD patients. Two reviewers independently assessed the risk of bias and extracted data. The primary outcome was 0-24 h weighted mean (wm) forced expiratory volume in the first second (FEV1), trough FEV1. The secondary outcomes were other lung functions, symptoms, quality of life, and safety. RESULTS: Three studies with 2119 patients were included in the meta-analysis. UMEC/VI showed improvement in 0-24 h wm FEV1 (mean difference (MD) 0.08 L, 95% confidence interval (CI) 0.06 to 0.10, P < 0.01, moderate quality) and trough FEV1 (MD 0.09 L, 95% CI 0.07 to 0.11, P < 0.01, moderate quality) in comparison with FP/SAL. UMEC/VI statistically significantly improved all other lung functions compared with FP/SAL. However, there were no significant differences between UMEC/VI and FP/SAL in rescue-medication use, symptomatic endpoints, and health outcomes. UMEC/VI also demonstrated fewer drug-related adverse effects (risk ratio 0.47, 95% CI 0.27 to 0.82, P = 0.01, low quality). CONCLUSIONS: UMEC/VI, when compared with FP/SAL, demonstrated significant improvements in lung functions with fewer drug-related adverse effects. However, the conclusion was limited by the scarcity of studies and long-term trials.

Surface charge manipulation for improved humidity sensing of TEMPO-oxidized cellulose nanofibrils.

Cellulose-based humidity sensors have attracted great research interest due to their hydrophilicity, biodegradability, and low cost. However, they still suffer from relatively low humidity sensitivity. Due to the presence of negatively charged carboxylate groups, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibril (CNF) exhibits enhanced hydrophilicity and ion conductivity, which is considered a promising candidate for humidity sensing. In this work, we developed a facile strategy to improve the humidity sensitivity of CNF films by regulating their surface charge density. With the increase in surface charge density, both water uptake and charge carrier densities of the CNF films can be improved, enabling a humidity sensitivity of up to 44.5 % (%RH)-1, higher than that of most polymer-based humidity sensors reported in the literature. Meanwhile, the sensor also showed good linearity (R2 = 0.998) over the 15-75 % RH at 1 kHz. With these features, the CNF film was further demonstrated for applications in noncontact sensing, such as human respiration, moisture on fingertips, and water leakage, indicating the great potential of CNF film in humidity monitoring.

Uridine diphosphate glucosyltransferase is vital for fenpropathrin resistance in Bombyx mori (Lepidoptera).

The silkworm (Bombyx mori) is an important model lepidopteran insect and can be used to identify pesticide resistance-related genes of great significance for biological control of pests. Uridine diphosphate glucosyltransferases (UGTs), found in all organisms, are the main secondary enzymes involved in the metabolism of heterologous substances. However, it remains uncertain if silkworm resistance to fenpropathrin involves UGT. This study observes significant variations in BmUGT expression among B. mori strains with variable fenpropathrin resistance post-feeding, indicating BmUGT's role in fenpropathrin detoxification. Knockdown of BmUGT with RNA interference and overexpression of BmUGT significantly decreased and increased BmN cell activity, respectively, indicating that BmUGT plays an important role in the resistance of silkworms to fenpropathrin. In addition, fenpropathrin residues were significantly reduced after incubation for 12 h with different concentrations of a recombinant BmUGT fusion protein. Finally, we verified the conservation of UGT to detoxify fenpropathrin in Spodoptera exigua: Its resistance to fenpropathrin decreased significantly after knocking down SeUGT. In a word, UGT plays an important role in silkworm resistance to fenpropathrin by directly degrading the compound, a function seen across other insects. The results of this study are of great significance for breeding silkworm varieties with high resistance and for biological control of pests.

Synthesis of dual models multivalent activatable aptamers based on HCR and RCA for ultrasensitive detection of Salmonella typhimurium.

Aptamers have superior structural properties and have been widely used in bacterial detection methods. However, the problem of low affinity still exists in complex sample detection. In contrast, hybridization chain reaction (HCR)-based model I and rolling circle amplification (RCA)-based model II multivalent activatable aptamers (multi-Apts) can fulfill the need for low-cost, rapid, highly sensitive and high affinity detection of S. typhimurium. In our research, two models of multi-Apts were designed. First, a monovalent activatable aptamer (mono-Apt) was constructed by fluorescence resonance energy transfer (FRET) with an S. typhimurium aptamer and its complementary chain of BHQ1. Next, the DNA scaffold was obtained by HCR and RCA, and the multi-Apts were obtained by self-assembly of the mono-Apt with a DNA scaffold. In model I, when target was presented, the complementary chain BHQ1 was released due to the binding of multi-Apts to the target and was subsequently adsorbed by UIO66. Finally, a FRET-based fluorescence detection signal was obtained. In mode II, the multi-Apts bound to the target, and the complementary chain BHQ1 was released to become the trigger chain for the next round of amplification of HCR with a fluorescence detection signal. HCR and RCA based multi-Apts were able to detect S. typhimurium as low as 2 CFU mL-1 and 1 CFU mL-1 respectively. Multi-Apts amplification strategy provides a new method for early diagnosis of pathogenic microorganisms in foods.

Extended survival with metastatic pancreatic cancer under fruquintinib treatment after failed chemotherapy: Two case reports.

BACKGROUND: Pancreatic cancer is a highly malignant disease. After decades of treatment progress, the current five-year survival rate for patients is still less than 10%. For later-line treatment, the treatment options are even more limited. Anti-angiogenic drugs can improve progression-free survival in patients with advanced pancreatic cancer. Preclinical data show that fruquintinib might improve the prognosis of advanced pancreatic cancer by targeting angiogenesis and lymphopoiesis, improving the abnormal vascular structure, and modulating the tumour immune microenvironment. CASE SUMMARY: We present two cases of third-line fruquintinib monotherapy that brought an extraprolonged progress-free survival (PFS) of 10 months. Patient 1 took adjuvant gemcitabine-based and first-line nab-paclitaxel-based chemotherapy and then used local radiotherapy combined with programmed cell death 1 receptor (PD-1). Each line lasted approximately 7 months. Moreover, the patient took third-line fruquintinib, which was followed by stable disease for 10 months, during which no additional adverse effect was observed. The patient later refused to take fruquintinib due to difficulty urinating and lower abdominal pain after the coronavirus disease 2019 (COVID-19) infection. The patient died in February 2023. Patient 2 also took two prior lines of chemotherapy and then local radiotherapy combined with S-1. After confirmed disease progression, the patient experienced a continuous partial response after using fruquintinib monotherapy in the third line. After the patient had COVID-19 in December 2022, fruquintinib was discontinued. The patient died in January 2023 due to disease progression. CONCLUSION: Both cases achieved a PFS benefit from later-line single-agent fruquintinib therapy. With its better safety profile, fruquintinib may be worth exploring and studying in more depth as a later-line treatment for pancreatic cancer patients.

Unveiling diverse coordination-defined electronic structures of reconstructed anatase TiO2(001)-(1 × 4) surface.

Transition metal oxides (TMOs) exhibit fascinating physicochemical properties, which originate from the diverse coordination structures between the transition metal and oxygen atoms. Accurate determination of such structure-property relationships of TMOs requires to correlate structural and electronic properties by capturing the global parameters with high resolution in energy, real, and momentum spaces, but it is still challenging. Herein, we report the determination of characteristic electronic structures from diverse coordination environments on the prototypical anatase-TiO2(001) with (1 × 4) reconstruction, using high-resolution angle-resolved photoemission spectroscopy and scanning tunneling microscopy/atomic force microscopy, in combination with density functional theory calculation. We unveil that the shifted positions of O 2s and 2p levels and the gap-state Ti 3p levels can sensitively characterize the O and Ti coordination environments in the (1 × 4) reconstructed surface, which show distinguishable features from those in bulk. Our findings provide a paradigm to interrogate the intricate reconstruction-relevant properties in many other TMO surfaces.

Electrochemiluminescence detection of diazinon in vegetables based on the synergistic interaction of WO3-x dots with Au@SiO2 nanocapsules.

In this work, a simple synthesis of low-toxicity transition metal material of WO3-x dots was used as a co-reactant with Au@SiO2 as a core-shell material and a signal amplification factor to collaboratively promote Ru(bpy)32+ electrochemiluminescence (ECL) for the construction of a highly sensitive aptasensor for the detection of diazinon (DZN) in vegetables. Electrodes modified with multi-walled carbon nanotubes-chitosan composite membranes (MWCNTs-CS) were used to load and immobilize more Ru(bpy)32+.can load more Ru(bpy)32+. WO3-x dots synthesized by a simple method showed excellent ECL efficiency as a novel co-reactant for Ru(bpy)32+. Under optimized conditions, this aptasensor for DZN has a wide detection range (10 pg mL-1 - 1 µg mL-1.) and a low detection limit (0.0197 ng L-1). The aptasensor has shown good results in the analysis of real samples in the experiment. This work provides a new approach to the construction of a novel electrochemiluminescence sensor for the detection of pesticides.

Effect of hornification on the isolation of anionic cellulose nanofibrils from Kraft pulp via maleic anhydride esterification.

Cellulose nanofibrils (CNF) isolation based on a catalyst-free maleic anhydride esterification has proven to be effective, however, the effects of pulp hornification on CNF isolation by this strategy have yet to be explored, which could present significant impacts for CNF isolation. Herein, dried northern bleached softwood Kraft pulp (D-NBSK) and never-dried northern bleached softwood Kraft pulp (ND-NBSK) were selected as the substrates. After esterification with maleic anhydride (MA), the esterified ND-NBSK pulp (E-ND) shows a significantly smaller size and more fragmented structure than the esterified D-NBSK pulp (E-D). Meanwhile, higher degree of esterification can be realized for the never dried pulp as compared to the dried pulp, which is corroborated by the significantly stronger characteristic peaks of CO (1720 cm-1) and -COO- (1575 cm-1) from the FTIR spectra and the higher surface charge content (0.86 ± 0.04 mmol/g vs. 0.55 ± 0.05 mmol/g). A comparison of the characteristics of the resulting CNF similarly demonstrated the negative impact of hornification. Overall, this work indicates that hornification tends to reduce the accessibility of chemical reagents to the pulp, leading to insufficient deconstruction. Such negative impact of hornification should be considered when performing nanocellulose isolation, especially when using pulp as feedstock.

A Biomimetic "Salting Out-Alignment-Locking" Tactic to Design Strong and Tough Hydrogel.

Recently, hydrogel-based soft materials have demonstrated huge potential in soft robotics, flexible electronics as well as artificial skins. Although various methods are developed to prepare tough and strong hydrogels, it is still challenging to simultaneously enhance the strength and toughness of hydrogels, especially for protein-based hydrogels. Herein, a biomimetic "salting out-alignment-locking" tactic (SALT) is introduced for enhancing mechanical properties through the synergy of alignment and the salting out effect. As a typical example, tensile strength and modulus of initially brittle gelatin hydrogels increase 940 folds to 10.12 ± 0.50 MPa and 2830 folds to 34.26 ± 3.94 MPa, respectively, and the toughness increases up to 1785 folds to 14.28 ± 3.13 MJ m-3. The obtained strength and toughness hold records for the previously reported gelatin-based hydrogel and are close to the tendons. It is further elucidated that the salting out effect engenders hydrophobic domains, while prestretching facilitates chain alignment, both synergistically contributing to the outstanding mechanical properties. It is noteworthy that the SALT demonstrates remarkable versatility across different salt types and polymer systems, thus opening up new avenues for engineering strong, tough, and stiff hydrogels.

Gastric point-of-care ultrasonography in patients undergoing radical gastrointestinal surgery before anesthetic induction: an observational cohort study.

BACKGROUND: Pulmonary aspiration of gastric contents is a serious perioperative complication. Patients with gastric cancer may experience delayed gastric emptying. However, the role of qualitative and quantitative gastric ultrasound assessments in this patient population before anesthesia induction has not yet been determined. METHODS: Adult patients with gastrointestinal cancer were recruited and examined using gastric point-of-care ultrasound (POCUS) before anesthetic induction from March 2023 to August 2023 in a tertiary cancer center. Three hundred patients with gastric cancer were conducted with POCUS prior to induction, and three hundred patients with colorectal cancer were included as controls. The cross-sectional area (CSA) of the gastric antrum and gastric volumes (GV) were measured and calculated. We determined the nature of the gastric contents and classified the antrum using a 3-point grading system. A ratio of GV to body weight > 1.5mL/Kg was defined as a high risk of aspiration. RESULTS: In patients with gastric cancer, 70 patients were classified as grade 2 (23%, including 6 patients with solid gastric contents) and 63 patients (21%) were identified as having a high risk of aspiration. Whereas in patients with colorectal cancer, only 11 patients were classified as grade 2 (3.7%), and 27 patients (9.7%) were identified as having a high risk of aspiration. A larger tumor size (OR:1.169, 95% CI 1.045-1.307, P = 0.006), tumor located in antrum (OR:2.304, 95% CI 1.169-4.539,P = 0.016), gastrointestinal obstruction (OR:21.633, 95% CI 4.199-111.443, P < 0.0001) and more lymph node metastasis (OR:2.261, 95% CI 1.062-4.812, P = 0.034) were found to be positively while tumor site at cardia (OR:0.096, 95% CI 0.019-0.464, P = 0.004) was negatively associated with high aspiration risk in patients with gastric cancer. CONCLUSION: The Gastric POCUS prior to induction provides an assessment of the status of gastric emptying and can identify the patients at high risk of aspiration, especially those with gastric cancer. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( www.chictr.org.cn ) identifier: ChiCTR2300069242; registered 10 March 2023.

La-Ce-MOF nanocomposite coated quartz crystal microbalance gas sensor for the detection of amine gases and formaldehyde.

Trimethylamine (TMA), Dimethylamine (DMA), Ammonia (NH3) and formaldehyde (HCHO) are typical volatile gases and able to cause great damage to the environment and the human body, and they may appear along in some particular cases such as marine meat spoilage. However, gas sensors can detect all the 4 hazardous gases simultaneously have rarely been reported. In this study, a quartz crystal microbalance (QCM) gas sensor modified with La-Ce-MOF was employed for the detection of 4 target gases (TMA, DMA, NH3 and HCHO). The sensor exhibited excellent stability (63 days), selectivity (3.51 Hz/(µmoL/L) for TMA, 4.19 Hz/(µmoL/L) for DMA, 3.14·Hz/(µmoL/L) for NH3 and 3.08·Hz/(µmoL/L) for HCHO), robustness and sensitivity towards target gases detection. Vienna Ab-initio Simulation Package calculations showed that this superior sensing performance was attributed to the preferential adsorption of target gas molecules onto the nanomicrospheres via hydrogen bond. The adsorption energy was - 0.4329 eV for TMA, - 0.5204 eV for DMA, - 0.6823 eV for NH3 and - 0.7576 eV for HCHO, all of which are physically adsorbed. In the detection of hazardous gases, sensor surface active sites were often susceptible to environmental factors and interfering substances, leading to a decrease in the sensitivity of the gas sensor, which in turn affects the signal accuracy in practical applications. This issue has been effectively addressed and the sensor has been implemented for the assessment of the salmon meat freshness, which may contribute to further advancements in the development of QCM gas sensors for monitoring food quality, human beings health and environment safety.

Near-Infrared Persistent Luminescence Nanoprobe for Early Detection of Atherosclerotic Plaque.

Atherosclerosis (AS) is a crucial contributor to various cardiovascular diseases (CVDs), which seriously threaten human life and health. Early and accurate recognition of AS plaques is essential for the prevention and treatment of CVD. Herein, we introduce an AS-targeting nanoprobe based on near-infrared (NIR) persistent luminescence nanoparticles (PLNPs), developing a highly sensitive NIR persistent luminescence (PersL) AS plaque imaging technique and successfully realizing early AS plaque detection. The nanoprobe exhibits good monodispersity and regular spherical morphology and also owns exceptional NIR PersL performance upon repetitive irradiation by biological window light. The surface-conjugated antibody (anti-osteopontin) endowed nanoprobe excellent targeting ability to foam cells within plaques. After intravenously injected nanoprobe into AS model mice, the highly sensitive PersL imaging technique can accurately detect AS plaques prior to ultrasonography (US) and magnetic resonance imaging (MRI). Specifically, the NIR PersL imaging reveals AS plaques at the earliest within 2 weeks, with higher signal-to-background ratio (SBR) up to 5.72. Based on this technique, the nanoprobe has great potential for applications in the prevention and treatment of CVD, the study of AS pathogenesis, and the screening of anti-AS drugs.

Development of pH-freshness smart label based on gellan gum film incorporated with red cabbage anthocyanins extract and its application in postharvest mushroom.

Novel colorimetric films based on gellan gum (GG) containing red cabbage anthocyanins extract (RCAE) were prepared as pH-freshness smart labels for real-time visual detection of mushroom freshness. The GG/RCAE films had excellent pH and ammonia sensitivity. The GG/RCAE-0.2-0.3 films had the highest sensitivity to acetic acid. The SEM micrographs, AFM images, FT-IR and XRD spectra demonstrated that RCAE were successfully combined into the film-forming substrate. The incorporation of RCAE resulted in the increase of thermal stability, opacity and surface hydrophobicity of films. Meanwhile, the GG/RCAE-0.2 film exhibited stronger tensile strength and excellent color stability at 4℃. The color changes of GG/RCAE-0.2 film were visually easier to distinguish during the storage of mushroom. The results showed the GG/RCAE films could be used as pH-freshness smart labels to detect the freshness of fruits and vegetables.

Does Baseline Cognitive Function Predict the Reduction Rate in HDRS-17 Total Scores in First-Episode, Drug-Naïve Patients with Major Depressive Disorder?

Purpose: Major depressive disorder (MDD) is associated with worse cognitive functioning. We aim to examine the association between baseline cognitive functioning and the reduction rate in HDRS-17 total scores and to highlight the predictors of the reduction rate in HDRS-17 total scores in MDD with first-episode, drug-naïve (FED) patients. Patients and Methods: Ninety FED patients were recruited consecutively and evaluated using the 17-item Hamilton Depression Rating Scale (HDRS-17), the 14-item Hamilton Anxiety Scale (HAMA-14), the Functioning Assessment Short Test (FAST) and the MATRICS Consensus Cognitive Battery (MCCB) at baseline and again at week 8. Results: Eighty-four FED patients completed the study. Comparison showed that response group had significantly higher T scores in TMT-A, BACS-SC, WMS-III, BVMT-R, MSCEI and CPT-IP, but showed significantly lower scores in FAST total scores including autonomy, occupational functioning, cognitive functioning, interpersonal relationship than non- response group (all p's< 0.05). Partial correlation analysis also found that the reduction rate in HDRS-17 total scores could be negatively associated with autonomy, cognitive functioning and interpersonal relationship domains as well as total FAST scores, also was further positively associated with T-scores of BACS-SC, CPT-IP and MSCEI in MCCB, even when accounting for potential confounders. Furthermore, the levels of cognitive function domain, autonomy domain in FAST, and BACS-SC, CPT-IP in MCCB may predict the reduction rate in HDRS-17 total scores in FED patients (all p's< 0.05). Conclusion: Our findings underscore significant correlations between baseline functioning and the reduction rate in HDRS-17 total scores in FED patients. Moreover, better baseline cognitive function, autonomy, speed of processing and attention/vigilance are more likely to predict patients' response to antidepressant treatment, indicating pre-treatment better cognitive functioning may be predictors to treatment response in FED.

Advances in signal amplification strategies applied in pathogenic bacteria apta-sensing analysis-A review.

Pathogenic bacteria are primarily kinds of food hazards that provoke serious harm to human health via contaminated or spoiled food. Given that pathogenic bacteria continue to reproduce and expand once they contaminate food, pathogenic bacteria of high concentration triggers more serious losses and detriments. Hence, it is essential to detect low-dose pollution at an early stage with high sensitivity. Aptamers, also known as "chemical antibodies", are oligonucleotide sequences that have attracted much attention owing to their merits of non-toxicity, small size, variable structure as well as easy modification of functional group. Aptamer-based bioanalysis has occupied a critical position in the field of rapid detection of pathogenic bacteria. This is attributed to the unique advantage of using aptamers as recognition elements in signal amplification strategies. The signal amplification strategy is an effective means to improve the detection sensitivity. Some diverse signal amplification strategies emphasize the synthesis and assembly of nanomaterials with signal amplification capabilities, while others introduce various nucleic acid amplification techniques into the detection system. This review focuses on a variety of signal amplification strategies employed in aptamer-based detection approaches to pathogenic bacteria. Meanwhile, we provided a detailed introduction to the design principles and characteristics of signal amplification strategies, as well as the improvement of sensor sensitivity. Ultimately, the existing issues and development trends of applying signal amplification strategies in apta-sensing analysis of pathogenic bacteria are critically proposed and prospected. Overall, this review discusses from a new perspective and is expected to contribute to the further development of this field.

Fluorescent aptasensor mediated with multiple ssDNA for sensitive detection of acetamiprid in vegetables based on magnetic Fe3O4/C-assisted separation.

Acetamiprid (ACE) is a highly effective broad-spectrum insecticide, and its widespread use is potentially harmful to human health and environmental safety. In this study, magnetic Fe3O4/carbon (Fe3O4/C), a derivative of metal-organic framework MIL-101 (Fe), was synthesized by a two-step calcination method. And a fluorescent sensing strategy was developed for the efficient and sensitive detection of ACE using Fe3O4/C and multiple complementary single-stranded DNA (ssDNA). By using aptamer with multiple complementary ssDNA, the immunity of interference of the aptasensor was improved, and the aptasensor showed high selectivity and sensitivity. When ACE was present, the aptamer (Apt) combined with ACE. The complementary strand of Apt (Cs1) combined with two short complementary strands of Cs1, fluorophore 6-carboxyfluorescein-labeled complementary strand (Cs2-FAM) and the other strand Cs3. The three strands formed a double-stranded structure, and fluorescence would not be quenched by Fe3O4/C. In the absence of ACE, Cs2-FAM would be in a single-chain state and would be adsorbed by Fe3O4/C, and the fluorescence of FAM would be quenched by Fe3O4/C via photoelectron transfer. This aptasensor sensitively detected ACE over a linear concentration range of 10-1000 nM with a limit of detection of 3.41 nM. The recoveries of ACE spiked in cabbage and celery samples ranged from 89.49% to 110.76% with high accuracy.

Shared hairpin structure electrochemiluminescence biosensor based on Au@Ni-Co metal organic frameworks for simultaneous detection of Pb(II) and S.aureus.

The excessive content of lead (Pb(II)) and Staphylococcus aureus (S.aureus) seriously harms the quality of aquatic products. In this paper, a highly sensitive electrochemiluminescence (ECL) biosensor was constructed using the synergistic effect of Au NPs@Nickel-Cobalt-Metal-organic frameworks (Au@Ni-Co-MOFs) and double potential resolution function of urchin-like Au@luminol and Cadmium sulfide quantum dots (CdS QDs) for synchronous detection of Pb(II) and S.aureus in aquatic products. Au@Ni-Co-MOFs as the base material, its cube structure can improve the surface active area and sensitivity of the sensor, providing more catalytic active sites for the two functional probes. Urchin-like Au@luminol binding aptamer DNA2 specifically recognizes Pb(II), CdS QDs binding aptamer DNA3 specifically recognizes S.aureus, which collaboratively catalyzed hydrogen peroxide reduction to produce two electrochemiluminescence signals. The shared hairpin structure DNA1 binds stably to Au@Ni-Co-MOFs via the Au-S bond, and the two functional probes are complementary paired with the DNA1 respectively to ensure the specificity of the aptamer. According to the ECL intensity changes of different potentials signal sources, the synchronous detection of Pb(II) and S.aureus with different concentrations is realized. The sensor realizes the detection of two targets in aquatic products and provides a new strategy for the simultaneous detection of multiple targets.

Novel electrochemiluminescence aptasensor based on AuNPs-ABEI encapsulated TiO2 nanorod for the detection of acetamiprid residues in vegetables.

Gold nanoparticles (AuNPs)@N-(4-aminobutyl)-N-ethylisoluminol (ABEI)@Titanium dioxide nanorods (TiO2NRs) were used as sensing materials to produce a unique encapsulated nanostructure aptasensor for the detection of acetamiprid residues in this work. ABEI, an analog of luminol, was extensively used as an electrochemiluminescence (ECL) reagent. The ECL mechanism of ABEI- hydrogen peroxide (H2O2) system had connections to a number of oxygen-centered free radicals. TiO2NRs improved ECL response with high electron transfer and a specific surface area. AuNPs were easy to biolabel and could catalyze H2O2 to enhance ECL signal. AuNPs were wrapped around TiO2NRs by utilizing the reduction property of ABEI to form wrapped modified nanomaterials. The sulfhydryl-modified aptamer bound to the nanomaterial by forming gold-sulfur (Au-S) bonds. The aptamer selectively bound to its target with the addition of acetamiprid, which caused a considerable decrease in ECL intensity and enabled quantitative detection of acetamiprid. The aptasensor showed good stability, repeatability and specificity with a broad detection range (1×10-2-1×103 nM) and a lower limit of detection (3 pM) for acetamiprid residues in vegetables. Overall, this aptasensor presents a simple and highly sensitive method for ECL detecting acetamiprid, with potential applications in vegetable safety monitoring.

Research progress on preparation methods and sensing applications of molecularly imprinted polymer-aptamer dual recognition elements.

The aptamer (Apt) and the molecularly imprinted polymer (MIP), as effective substitutes for antibodies, have received widespread attention from researchers because of their creation. However, the low stability of Apt in harsh detection environment and the poor specificity of MIP have hindered their development. Therefore, some researchers have attempted to combine MIP with Apt to explore whether the effect of "1 + 1 > 2" can be achieved. Since its first report in 2013, MIP-Apt dual recognition elements have become a highly focused research direction in the fields of biology and chemistry. MIP-Apt dual recognition elements not only possess the high specificity of Apt and the high stability of MIP in harsh detection environment, but also have high sensitivity and affinity. They have been successfully applied in medical diagnosis, food safety, and environmental monitoring fields. This article provides a systematic overview of three preparation methods for MIP-Apt dual recognition elements and their application in eight different types of sensors. It also provides effective insights into the problems and development directions faced by MIP-Apt dual recognition elements.