[A study on the dual use of e-cigarettes and cigarettes among adolescents in Shandong Province]

Objective: To understand the current status and its associated factors of dual use of e-cigarettes and cigarettes among adolescents in Shandong Province and explore the reasons for dual use behavior. Methods: A self-administered survey was conducted among 7 999 middle school students who were selected by stratified multi-stage cluster sample method. Data were weighted and analyzed by the SPSS 25.0 complex program. Results: In Shandong Province, the prevalence rates of attempting and current dual use of e-cigarettes and cigarettes among adolescents appeared as 7.7% and 1.3%, respectively. Male, friends smoking, and secondhand smoke exposure in the past 7 days were risk factors for dual use. Compared with cigarette smokers, dual users have no differences in cognition and behavior in quitting smoking (P>0.05). The main reason for dual users to smoke e-cigarettes was curiosity. Conclusions: Dual use of e-cigarettes and cigarettes is common among adolescents in Shandong Province, and its influencing factors are similar to traditional cigarettes. Dual use is not a transitional stage for smoking cessation. Dual users are more likely to continue smoking in the future, which should be paid attention and concern.

Gold nanoparticle-decorated covalent organic frameworks as amplified light-scattering probes for highly sensitive immunodetection of Salmonella in milk

Traditional immunoassays exhibit insufficient screening sensitivity for foodborne pathogens due to their low colorimetric signal intensities. Herein, we propose an ultrasensitive dynamic light scattering (DLS) immunosensor for Salmonella based on a "cargo release-seed growth" strategy enabled by a probe, namely gold nanoparticle-decorated covalent organic frameworks (COF@AuNP). Large amounts of AuNPs in COF@AuNP can be released by acid treatment-induced decomposition of the imine-linked COF, and then they are enlarged via gold growth to generate a dramatically enhanced light-scattering signal, leading to a vast improvement in detection sensitivity. Based on an immunomagnetic microbead carrier, the proposed DLS immunosensor is capable of detecting trace Salmonella in milk in the range of 2.0 × 102-2.0 × 105 CFU mL-1, with a limit of detection of 60 CFU mL-1. The immunosensor also demonstrated excellent selectivity, good accuracy and precision, and high reliability for detecting Salmonella in milk.

Effect of emodin combined with cisplatin on the invasion and migration of HepG2 hepatoma cells

Cisplatin is the leading chemotherapy agent for advanced liver cancer. However, the resistance to cisplatin in liver cancer reduces its efficacy. A potential strategy to increase its effectiveness and reduce toxicity is to combine cisplatin with 1,3,8-trihydroxy-6-methylanthraquinone (emodin). In this study, we examined the effects of emodin combined with cisplatin on the invasion and migration of HepG2 cells and analyzed the role of emodin. The effects of cisplatin, emodin and their combination were assessed in HepG2 cells. Proliferation, invasion and migration of HepG2 cells were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), scar and Transwell assays. The gelatinase spectrum and an ELISA detected the expression of matrix metallopeptidase 2 (MMP-2) and matrix metallopeptidase 9 (MMP-9). The expression of E-cadherin and vimentin was detected by immunofluorescence and Western blots. Emodin inhibited cell invasion and migration in HepG2 hepatoma cells, increased E-cadherin expression, decreased vimentin, MMP-2, and MMP-9 expression. The combination of emodin and cisplatin-induced a more significant effect in a dose-dependent manner. In this study, we found that emodin inhibited hepatocellular carcinoma (HCC) metastasis. Compared with either cisplatin or emodin alone, the combination of both showed a more significant synergistic effect. Emodin can enhance the sensitivity of HepG2 HCC cells to cisplatin by inhibiting epithelial-mesenchymal transition, and thus, play a role in preventing recurrence and metastasis in HCC.

A label-free fiber ring laser biosensor for ultrahigh sensitivity detection of Salmonella Typhimurium

The rapid detection of low concentrations of Salmonella Typhimurium (S. Typhimurium) is an essential preventive measure for food safety and prevention of foodborne illness. The study presented in this paper addresses this critical issue by proposing a single mode-tapered seven core-single mode (STSS) fiber ring laser (FRL) biosensor for S. Typhimurium detection. The experimental results show that the specific detection time of S. Typhimurium is less than 20 min and the wavelength shift can achieve -0.906 nm for an S. Typhimurium solution (10 cells/mL). Furthermore, at a lower concentration of 1 cell/mL applied to the biosensor, a result of -0.183 nm is observed in 9% of samples (1/11), which indicates that the proposed FRL biosensor has the ability to detect 1 cell/mL of S. Typhimurium. In addition, the detection results in chicken and pickled pork samples present an average deviation of -27% and -23%, respectively, from the measured results in phosphate buffered saline. Taken together, these results show the proposed FRL biosensor may have potential applications in the fields of food safety monitoring, medical diagnostics, etc.

Ultrasensitive Lateral Flow Immunoassay for Fumonisin B1 Detection Using Highly Luminescent Aggregation-Induced Emission Microbeads

Lateral flow immunoassay (LFIA) based on fluorescent microbeads has attracted much attention for its use in rapid and accurate food safety monitoring. However, conventional fluorescent microbeads are limited by the aggregation-caused quenching effect of the loaded fluorophores, thus resulting in low signal intensity and insufficient sensitivity of fluorescent LFIA. In this study, a green-emitting fluorophore with an aggregation-induced emission (AIE) characteristic was encapsulated in polymer nanoparticles via an emulsification technique to form ultrabright fluorescent microbeads (denoted as AIEMBs). The prepared AIEMBs were then applied in a competitive LFIA (AIE-LFIA) as signal reporters for the rapid and highly sensitive screening of fumonisin B1 (FB1) in real corn samples. High sensitivity with a detection limit of 0.024 ng/mL for FB1 was achieved by the developed AIE-LFIA. Excellent selectivity, good accuracy, and high reliability of the AIE-LFIA were demonstrated, indicating a promising platform for FB1 screening.

Bifunctional M13 Phage as Enzyme Container for the Reinforced Colorimetric-Photothermal Dual-Modal Sensing of Ochratoxin A

"Point of care" (POC) methods without expensive instruments and special technicians are greatly needed for high-throughput analysis of mycotoxins. In comparison, the most widely used screening method of the conventional enzyme-linked immunosorbent assay (ELISA) confronts low sensitivity and harmful competing antigens. Herein, we develop a plasmonic-photothermal ELISA that allows precise readout by color-temperature dual-modal signals based on enzymatic reaction-induced AuNP aggregation for highly sensitive detection of ochratoxin A (OTA). The bifunctional M13 phage carrying OTA that mimics the mimotope on the end of p3 proteins and abundant biotin molecules on the major p8 proteins is adopted as an eco-friendly competing antigen and enzyme container for amplifying the signal intensity. Under optimal conditions, both colorimetric and photothermal signals enable good dynamic linearity for quantitative OTA detection with the limits of detection at 12.1 and 8.6 pg mL-1, respectively. Additionally, the proposed ELISA was adapted to visual determination with a cutoff limit of 78 pg mL-1 according to a vivid color change from deep blue to red. The recoveries of OTA-spiked corn samples indicate the high accuracy and robustness of the proposed method. In conclusion, our proposed strategy provides a promising method for eco-friendly and sensitive POC screening of OTA. Moreover, it can be easily applied to other analytes by changing the involved specific mimotope sequence.

M13 bacteriophage as biometric component for orderly assembly of dynamic light scattering immunosensor

The ordered assembly of nanostructure is an effective strategy used to manipulate the hydrodynamic diameter (D_H) of nanoparticles. Herein, a versatile dynamic light scattering (DLS) immunosensing platform is presented to sensitively detect small molecules and biomacromolecules by using the M13 phage as the building module to order the assembly of gold nanoflowers and gold-coated magnetic nanoparticles, respectively. After the directional assembly of M13 phage, the D_H of the probes was significantly increased due to its larger filamentous structure, thus improving the detection sensitivity of the DLS immunosensor. The designed M13 assembled DLS immunosensor with competitive and sandwich formats showed high sensitivities for ochratoxin A and alpha-fetoprotein in real corn and undiluted serum samples, with the detection limits of 1.37 and 57 pg/mL, respectively. These values are approximately 15.8 and 164.9 times lower than those of traditional phage-based enzyme-linked immunosorbent assays. Collectively, this work provides a promising strategy to manipulate the D_H of nanoparticles by highly evolved biomaterials such as engineered M13 phages and opens upon a new direction for developing DLS immunosensors to detect various targets by the fusion expression of special peptide or nanobody on the pIII or pVIII protein of M13 phage.

[Clinical analysis of multiple myeloma with second primary malignancies and multiple myeloma secondary to malignancies]

Objective: To compare the clinical characteristics and survival outcomes of multiple myeloma (MM) with second primary malignancies (SPMs) and MM secondary to malignancies. Methods: The clinical data of MM patients diagnosed and treated in Beijing Chaoyang Hospital, Capital Medical University from January 2002 to January 2021 were included. The patients were divided into two groups: MM with SPMs group and MM secondary to malignancies group. The gender, age at first diagnosis, classification, stage, type of combined malignant tumor and the treatment were analyzed. The clinical characteristics and survival differences were compared between the two groups. Results: There were 20 patients in the MM with SPMs group, 9 males and 11 females, aged [M(Q₁,Q₃)] 61.5(56.8, 68.0)years, and the overall survival (OS) was 49.5(32, 58) months, while the time to death from secondary tumor was 12(4,21)months. There were 29 patients in the MM secondary to malignancies group, 13 males and 16 females, aged 64.0(57.0, 71.0)years, and the OS was 97(61, 171) months, while the time to death from secondary MM was 32(18, 47) months. The time from patients diagnosed with MM to SPMs was 37(18, 50) months, which was significantly earlier than that of MM secondary to malignancies [53(31,117) months](P=0.016). The type of tumor was also different between the two groups (P<0.001). In the group of MM with SPMs, the most common type of SPMs was hematopoietic malignancies (12/20, 60.0%), whereas in the group of MM secondary to malignancies, MM was most often secondary to genitourinary malignancies (13/29, 44.8%) (P<0.001). Conclusions: Both MM with SPMs and MM secondary to malignancies can affect the survival of patients. Secondary hematological malignancies account for a high proportion of the second tumors in MM patients, while genitourinary malignancies account for a high proportion of malignant tumors associated with MM.

[The prognostic value of dynamic minimal residual disease after autologous hematopoietic stem cell transplantation in patients with multiple myeloma in novel-agent era]

Objective: To investigate the clinical prognostic value of dynamic minimal residual disease (MRD) after autologous hematopoietic stem cell transplantation (AHSCT) in patients with multiple myeloma (MM). Methods: Patients with MM who underwent AHSCT in Beijing Chao-Yang Hospital from February 2016 to December 2019 were enrolled in this study. All the patients in the study had complete baseline data at the diagnosis. AHSCT was performed after induction chemotherapy. Response evaluation was performed after induction therapy. All the patients were assessed at approximately 100 days after AHSCT. Bone marrow MRD by NGF was performed every three months and dynamically monitored for at least 12 months. All the patients were divided into different groups according to cytogenetics and MRD status. Survivals in different groups were analyzed by IBM SPSS 22.0 statistical software. Results: A total of 150 patients with MM were enrolled in this study at last, including 66 patients in the cytogenetic standard risk group and 84 patients in the cytogenetic high-risk group. The median age was 54 years (range 30-68 years) and 87 male patients (58.0%) was in the study. The median follow-up was 36 months (range 16-72 months). Patients in the standard-risk group had better clinical prognosis than those in the high-risk group [median PFS in the standard-risk group was not achieved, and median PFS in the high-risk group was 45 months (P<0.001); median OS of both groups was not reached, and the estimated 3-year OS rate of the standard-risk group and the high-risk group was 95.2% and 78.9%, respectively (P=0.001)]. According to MRD status of patients, patients in each group were divided into three subgroups: persistent positive (Ppos), transient negative (Tneg) and persistent negative (Pneg). The median OS and median PFS of all subgroups in the standard-risk group was not reached (P=0.324 and P=0.086). In high-risk group, the median OS of MRD Pneg subgroup was not reached, and the estimated 3-year OS rate was 100%; The median OS of MRD Ppos subgroup was 52 months, and MRD Tneg subgroup only 31 months (P=0.002); the median PFS of MRD Pneg group was not reached, and the estimated 3-year PFS rate was 85.4%; median PFS of MRD Ppos subgroup was 40 months, and MRD Tneg subgroup only 17 months (P=0.001). Conclusions: MRD Pneg might overcome the adverse prognosis of MM patients with high-risk cytogenetics. However, MRD Tneg might be a poor prognostic factor for the patients with cytogenetic high-risk MM.

[An analysis on senior pupil's tobacco use and exposure in Shandong province in 2012 and 2019]

Objective: To analyze the changes in tobacco use and exposure in primary school students in Shandong province in 2012 and 2019. Methods: A multi-stage stratified cluster random sampling method was used in the survey. In 2012 and 2019, 5 861 and 4 021 students from 3 different cities of Shandong province were selected as the study population. The questionnaire was filled anonymously by the subjects. χ² test was conducted to compare the difference of groups. Results: In 2012 and 2019, the rate of attempting smoking among pupils under this study in Shandong province were 6.0％and 6.3%, respectively, while the current smoking rate were 1.2％and 2.3%, respectively. The sex ratio of male and female students attempting to smoke was 2.56∶1 in 2012 and 1.31∶1 in 2019. The sex ratio of current smoking rate was 2.43∶1 and 2.00∶1, respectively in 2012 and in 2019. The rate of tobacco exposure in the public places was 50.5％and 41.4%, respectively. The rate of tobacco exposure in family was 49.7% and 46.4%, respectively. Two rates of tobacco exposure decreased, but the reduction in family (3.3%) was far less than that in public places (9.1%). In 2019, the rate of tobacco exposure in family was higher than that in public places. Conclusions: The tobacco exposure rate declined in senior pupils in Shandong province. However, the situation is still grim for the current smoking rate, growth trend of girls tobacco use, and tobacco exposure in family.

The ins and outs of male breast and anterior chest wall lesions from childhood to adulthood

Physiological and pathological processes arising from the breast and anterior chest wall may share similar clinical presentations because of the small volume of male breasts. Therefore, imaging is frequently required to localise and characterise the lesion and guide biopsy when radiological findings are equivocal or suspicious. Mammography or digital breast tomosynthesis (DBT) and ultrasound are the mainstays of breast imaging work-up. Other imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and positron-emission tomography (PET) can sometimes augment the investigation and aid treatment planning. This article reviews the key imaging features of a wide spectrum of benign and malignant conditions that involve the male breast and anterior chest wall across various age groups. Familiarisation with the salient radiological findings is essential for reaching an accurate diagnosis and optimising management.

"Three-in-One" Multifunctional Nanohybrids with Colorimetric Magnetic Catalytic Activities to Enhance Immunochromatographic Diagnosis

Colorimetric lateral flow immunoassay (LFIA) with gold nanoparticles (AuNPs) as signal reporters has been widely used in point-of-care testing. Nonetheless, the potential of traditional AuNP-based LFIA for the early diagnosis of disease is often compromised by limited sensitivity due to the insufficient colorimetric signal brightness of AuNPs. Herein, we develop a "three-in-one" multifunctional catalytic colorimetric nanohybrid (Fe₃O₄@MOF@Pt) composed of Fe₃O₄ nanoparticles, MIL-100(Fe), and platinum (Pt) nanoparticles. Fe₃O₄@MOF@Pt displays enhanced colorimetric signal brightness, fast magnetic response, and ultrahigh peroxidase-mimicking activity, which are beneficial to the enhancement of the sensitivity of LFIA by coupling with magnetic separation and catalytic amplification. When integrated with the dual-antibody sandwich LFIA platform, the developed Fe₃O₄@MOF@Pt can achieve an ultrasensitive immunochromatographic assay of procalcitonin with a sensitivity of 0.5 pg mL^-1, which is approximately 2280-fold higher than that of conventional AuNP-based LFIA and superior to previously published immunoassays. Therefore, this work suggests that the proposed catalytic colorimetric nanohybrid can act as promising signal reporters to enable ultrasensitive immunochromatographic disease diagnostics.

Eco-Friendly Fluorescent ELISA Based on Bifunctional Phage for Ultrasensitive Detection of Ochratoxin A in Corn

Conventional enzyme-linked immunosorbent assay (ELISA) is commonly used for Ochratoxin A (OTA) screening, but it is limited by low sensitivity and harmful competing antigens of enzyme-OTA conjugates. Herein, a bifunctional M13 bacteriophage with OTA mimotopes fused on the p3 protein and biotin modified on major p8 proteins was introduced as an eco-friendly competing antigen and enzyme container for enhanced sensitivity. Mercaptopropionic acid-modified quantum dots (MPA-QDs), which are extremely sensitive to hydrogen peroxide, were chosen as fluorescent signal transducers that could manifest glucose oxidase-induced fluorescence quenching in the presence of glucose. On these bases, a highly sensitive and eco-friendly fluorescent immunoassay for OTA sensing was developed. Under optimized conditions, the proposed method demonstrates a good linear detection of OTA from 4.8 to 625 pg/mL and a limit of detection (LOD) of 5.39 pg/mL. The LOD is approximately 26-fold lower than that of a conventional horse radish peroxidase (HRP) based ELISA and six-fold lower than that of a GOx-OTA conjugate-based fluorescent ELISA. The proposed method also shows great specificity and accepted accuracy for analyzing OTA in real corn samples. The detection results are highly consistent with those obtained using the ultra-performance liquid chromatography-fluorescence detection method, indicating the high reliability of the proposed method for OTA detection. In conclusion, the proposed method is an excellent OTA screening platform over a conventional ELISA and can be easily extended for sensing other analytes by altering specific mimic peptide sequences in phages.

The alarmin interleukin-1α causes preterm birth through the NLRP3 inflammasome

Sterile intra-amniotic inflammation is a clinical condition frequently observed in women with preterm labor and birth, the leading cause of neonatal morbidity and mortality worldwide. Growing evidence suggests that alarmins found in amniotic fluid, such as interleukin (IL)-1α, are central initiators of sterile intra-amniotic inflammation. However, the causal link between elevated intra-amniotic concentrations of IL-1α and preterm birth has yet to be established. Herein, using an animal model of ultrasound-guided intra-amniotic injection of IL-1α, we show that elevated concentrations of IL-1α cause preterm birth and neonatal mortality. Additionally, using immunoblotting techniques and a specific immunoassay, we report that the intra-amniotic administration of IL-1α induces activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome in the fetal membranes, but not in the decidua, as evidenced by a concomitant increase in the protein levels of NLRP3, active caspase-1, and IL-1β. Lastly, using Nlrp3-/- mice, we demonstrate that the deficiency of this inflammasome sensor molecule reduces the rates of preterm birth and neonatal mortality caused by the intra-amniotic injection of IL-1α. Collectively, these results demonstrate a causal link between elevated IL-1α concentrations in the amniotic cavity and preterm birth as well as adverse neonatal outcomes, a pathological process that is mediated by the NLRP3 inflammasome. These findings shed light on the mechanisms underlying sterile intra-amniotic inflammation and provide further evidence that this clinical condition can potentially be treated by targeting the NLRP3 inflammasome.

[Survey on tobacco use and associated factors in population in Shandong province, 2016-2017]

Objective: To understand the status of tobacco use and related influencing factors in population in Shandong province. Methods: Stratified multi-stage cluster sampling was used to select respondents from 216 villages (communities) of 36 districts (counties) in Shandong province. Influencing factors on smoking were analyzed by logistic regression model. Results: The adequate sample size was 6 271 participants. After complex weighted, the current smoking prevalence was 23.93%,45.58% in males and 1.18% in females. The Public's smoking rates varied widely among different groups in the population. 45-64 age group had the highest smoking rate (25.07%). Smoking rates were substantially different in education levels, with the highest in junior high school (28.94%). The rate was higher in the rural area (24.98%) than that in the urban areas (23.08%). The average daily smoking rate was 20.23%. The average age of initiating smoking was 21.21 years. The average daily cigarette intake was 16.31 cigarettes. Among all the former and current smokers, the quitting rate was 20.79%. Multiple logistic regression model analysis showed that gender, age, occupation, region, and health knowledge score were correlated with smoking behavior. The current smoking rate of men was much higher than that of women (OR=49.625, 95%CI: 37.832-65.093). The current smoking rate in 45-64 age group was higher than that in the 15-24 age group (OR=1.830, 95%CI: 1.048-3.194). The current smoking rate of medical (OR=0.403, 95%CI: 0.187-0.866) and retired personnel (OR=0.648, 95%CI: 0.481-0.873) were lower than those engaging in agriculture, forestry, animal husbandry and the fishery ,respectively. The prevalence of residents living in the central part showed lower rate on current smoking than that in the eastern region (OR=0.724, 95%CI: 0.606-0.865). The current smoking prevalence of smoke hazard in 1-3 score group was higher than that in the group with 4-6 score (OR=1.432, 95%CI: 1.240-1.654). Conclusions: Smoking rate in adults in Shandong remained stable and at a high level. Comprehensive intervention measures such as tobacco control and health education should be carried out to reduce the smoking rate.

Gold Nanobeads with Enhanced Absorbance for Improved Sensitivity in Competitive Lateral Flow Immunoassays

BACKGROUND

Colloidal gold based lateral flow immunoassay (LFIA) commonly suffers from relatively low detection sensitivity due to the insufficient brightness of conventional gold nanoparticles (AuNPs) with the size of 20-40 nm.

METHODS

Herein, three kinds of gold nanobeads (GNBs) with the size of 94 nm, 129 nm, and 237 nm, were synthesized by encapsulating numerous hydrophobic AuNPs (10 nm) into polymer matrix. The synthesized GNBs exhibited the enhanced colorimetric signal intensity compared with 20-40 nm AuNPs. The effects of the size of GNBs on the sensitivity of LFIA with competitive format were assessed.

RESULTS

The results showed that the LFIA using 129 nm GNBs as amplified signal probes exhibits the best sensitivity for fumonisin B1 (FB1) detection with a cut-off limit (for visual qualitative detection) at 125 ng/mL, a half maximal inhibitory concentration at 11.27 ng/mL, and a detection limit at 1.76 ng/mL for detection of real corn samples, which are 8-, 3.82-, and 2.89-fold better than those of conventional AuNP40-based LFIA, respectively. The developed GNB-LFIA exhibited negligible cross-reactions with other common mycotoxins. In addition, the accuracy, precision, reliability, and practicability were demonstrated by determining real corn samples.

CONCLUSIONS

All in all, the proposed study provides a promising strategy to enhance the sensitivity of competitive LFIA via using the GNBs as amplified signal probes.

Recent advances in colorimetry/fluorimetry-based dual-modal sensing technologies

Tailored to the increasing demands for sensing technologies, the fabrication of dual-modal sensing technologies through combining two signal transduction channels into one method has been proposed and drawn considerable attention. The integration of two sensing signals not only promotes the analytical efficiency with reduced assumption, but also improves the analytical performances with enlarged detection linear range, enhanced accuracy, and boosted application flexibility. The two top-rated output signals for developing dual-modal sensors are colorimetric and fluorescent signals because of their outstanding merits for point of care applications and real-time sensitive sensing. Given the rapid development of material chemistry and nanotechnology, the recent decade has witnessed great advance in colorimetric/fluorimetric signal based dual-modal sensing technologies. The new sensing strategy leads to a broad avenue for various applications in disease diagnosis, environmental monitoring and food safety because of the complementary and synergistic effects of the two output signals. In this state-of-the-art review, we comprehensively summarize different types of colorimetric/fluorimetric dual-modal sensing methods by highlighting representative research in the last 5 years, digging into their sensing methodologies, particularly the working principles of the signal transduction systems. Then, the challenges and future prospects for boosting further development of this research field are discussed.

Integrated nanoparticle size with membrane porosity for improved analytical performance in sandwich immunochromatographic assay

The use of luminescent nanobeads to improve the sensitivity of sandwich immunochromatographic assay (ICA) has obtained increasing concern. Illustrating the relationship among luminescent intensity, nanobead size, nitrocellulose membrane aperture, and ICA sensitivity is important for achieving the optimal target detection. Thus, we synthesized six differently sized quantum dot beads (QBs) (95, 140, 180, 235, 325, and 405 nm) as ICA labels and applied them in three aperture membranes (10, 15, and 25 μm). Results indicate that increasing the QB size to less than an appropriate size of 235 nm is beneficial for ICA sensitivity because of the increased fluorescence. However, oversized QBs result in reduced sensitivity due to the decreased diffusion or settlement of the QB on the membrane that causes obvious background signal. The small aperture membrane perfectly matching the QB size contributes to ICA sensitivity by decreasing the migration velocity of the QB probe for increased binding of the QB@analyte complex at the T zone. Consequently, the best detection of hepatitis B surface antigen with a sensitivity of 0.156 ng/mL is achieved using 235 nm QBs in 15 μm membrane. Further performance evaluation of our QB₂₃₅-ICA_CN95 demonstrates excellent accuracy, selectivity, and practicability. This work provides a new idea to manipulate the sensitivity of sandwich ICA by tuning the QB size and the membrane aperture, and a theoretical guidance for selecting the probe and membrane to achieve the best detection of target analytes.

[Prevalence and associated factors regarding electronic cigarette smoking among adults in Shandong province]

Objective: To understand the awareness, current or past behavior on electronic cigarette smoking (ECS) and associated factors, among adults aged ≥15 years old in Shandong province. Relationship between ECS and cessation of smoking was also studied. Methods: Using the global standard questionnaire, a cross-sectional survey was conducted among 6 401 adults selected by stratified multi-stage cluster sample method. Electronic data was collected by handheld computer. Data were weighted and analyzed by SPSS 19.0 complex program. Results: The prevalence rates of awareness, ever or current smoking of e-cigarettes appeared as 37.6%, 3.8% and 0.6% respectively. Data from logistic regression analysis showed that risk factors for ECS were living in urban area, at younger age, being current or former cigarettes smoker and with knowledge on the risks of smoking or being encouraged to stop smoking. Among the electronic cigarettes smokers, those who tried to quit smoking (30.1%) had a significantly higher rate than that of the non-smokers (19.5%) (P<0.05), however, the successful quitting rate was much lower than that in the non-ECS users (P<0.05). Conclusions: Rates on the awareness and uptake of electronic cigarettes are on the rise. It is necessary to strengthen and standardize the monitoring programs to provide evidence for setting up targeting intervention strategies.

A novel magneto-gold nanohybrid-enhanced lateral flow immunoassay for ultrasensitive and rapid detection of ochratoxin A in grape juice

Conventional gold nanoparticle-based lateral flow immunoassay (LFIA) usually suffers a huge challenge in measuring target concentration in food matrices with dark color because of its poor resistance to the background matrix and color interference. To address this issue, we first report a novel bifunctional magneto-gold nanohybrid (MGNH) for the simultaneous magnetic separation and colorimetric target sensing by integrating MGNHs into LFIA. Under optimum conditions, an ultrasensitive detection of ochratoxin A (OTA) in grape juice was achieved with a limit of detection at 0.094 ng mL^-1. The average recoveries of this MGNH-LFIA ranged from 92.31% to 108.97% with a coefficient of variation of below 12%. The excellent selectivity of our MGNH-LFIA against OTA was demonstrated. Besides, our MGNH-LFIA is comparable to liquid chromatography coupled with mass spectrometry in terms of accuracy, reproducibility, and practicability. The designed MGNH-LFIA platform is readily extended for improving other small molecule detection in food samples.

AIEgens: An emerging fluorescent sensing tool to aid food safety and quality control

As a global public health problem, food safety has attracted increasing concern. To minimize the risk exposure of food to harmful ingredients, food quality and safety inspection that covers the whole process of "from farm to fork" is much desired. Fluorescent sensing is a promising and powerful screening tool for sensing hazardous substances in food and thus plays a crucial role in promoting food safety assurance. However, traditional fluorphores generally suffer the problem of aggregation-caused quenching (ACQ) effect, which limit their application in food quality and safety inspection. In this regard, luminogens with aggregation-induced emission property (AIEgens) showed large potential in food analysis since AIEgens effectively surmount the ACQ effect with much better detection sensitivity, accuracy, and robustness. In this contribution, we review the latest developments of food safety monitoring by AIEgens, which will focus on the molecular design of AIEgens and their sensing principles. Several examples of AIE-based sensing applications for screening food contaminations are highlighted, and future perspectives and challenges in this emerging field are tentatively elaborated. We hope this review can motivate new research ideas and interest to aid food safety and quality control, and facilitate more collaborative endeavors to advance the state-of-the-art sensing developments and reduce actual translational gap between laboratory research and industrial production.

Integrated gold superparticles into lateral flow immunoassays for the rapid and sensitive detection of Escherichia coli O157:H7 in milk

Escherichia coli O157:H7 is a common harmful foodborne pathogen that can cause severe diseases at low infectious doses. Traditional lateral flow immunoassay (LFIA) for the rapid screening of E. coli O157:H7 in food suffers from low sensitivity due to its dependence on 20- to 40-nm gold nanoparticles (AuNP) with insufficient brightness as labels. To address this issue, we reported for the first time the successful synthesis of gold superparticles (GSP) by encapsulating numerous small AuNP into a polymer nanobead using an evaporation-induced self-assembly method. Results indicated that the resultant GSP exhibited remarkably enhanced absorbance compared with the most widely used 40 nm AuNP in LFIA. In addition, the absorbance of GSP could be easily tuned by varying GSP sizes. Under optimized conditions, we achieved a rapid and sensitive determination of E. coli O157:H7 in milk with a detection limit of 5.95 × 10² cfu/mL when using the GSP with a size of 342 nm as LFIA signal reporters, exhibiting improvement of approximately 32-fold relative to the conventional 40 nm AuNP-LFIA method. We further demonstrated the selectivity, accuracy, reliability, and practicality of the proposed GSP-LFIA strip. In summary, this work offers a new strategy for improving LFIA sensitivity using assembled GSP as markers and demonstrates huge potential in rapidly and sensitively detecting foodborne pathogens.

1141 Daytime Napping Trajectory Over Time And Its Association With Cognitive Aging: A 13-year Community-based Longitudinal Study Of Older Adults

Introduction

Daytime napping is common in elderly adults and has been associated with cognitive impairment. Prior studies have assessed napping at one time point, making it difficult to examine the longitudinal progression of napping and its association with cognitive aging. We examined objectively measured daytime napping longitudinally across different stages of Alzheimer’s disease (AD): from no cognitive impairment (NCI), to mild cognitive impairment (MCI), and to Alzheimer’s dementia.

Methods

We studied 1,066 participants (female: 810; age: 81.0±7.3 [SD]) in the Rush Memory and Aging Project who have been followed for up to 13 years. Motor activities of up to 10 days were recorded annually and used to assess napping objectively. We defined daytime napping episodes as segments between 10AM and 7PM with continuous zero-activity for ≥10min but &lt;1h (to avoid off-wrist periods). Segments that were &lt;5min apart were merged. Cognitive and clinical evaluations were administered annually to render a clinical diagnostic classification of NCI, MCI, or Alzheimer’s dementia. To examine how napping duration and frequency change with the progression of AD, we performed linear mixed-effects models with 2 change points anchored at the diagnoses of MCI and AD while adjusted for age, sex, and education.

Results

At baseline, participants had 1.44±0.04 (mean±standard error) naps with an accumulated duration of 35.0±1.1 min per day. Napping duration increased by 5.2±0.3 min and frequency increased by 0.21±0.01 times every year (both p&lt;0.0001). The rate of increase was more than doubled after MCI diagnosis with an annual increase of 11.4±0.7 min in duration and 0.40±0.02 times in frequency (both p&lt;0.0001); these were doubled further after AD diagnosis with an annual change of 26.3±3.1 min in duration and 0.84±0.08 times in frequency (both p&lt;0.0001).

Conclusion

Daytime napping duration and frequency increase with aging, and the increase was accelerated with AD progression.

Support

This work was supported by NIH grants RF1AG064312, RF1AG059867, R01AG017917, and R01AG56352.

1145 Longitudinal Association Between Circadian Activity Rhythms And Risk Of Incident Parkinson’s Disease In Older Men

Introduction

Disruption in circadian activity rhythms are very common in older adults, particularly among those with neurodegenerative diseases. However, the longitudinal association between circadian disruption and subsequent risk of developing neurodegenerative diseases, including Parkinson’s disease (PD), is unclear.

Methods

We examined rest-activity rhythms in 2930 community-dwelling older men (mean age 76.3 ± 5.5 years) without PD and followed them for incident PD over the next 11 years. 24-h rest-activity rhythm parameters (amplitude, mesor, robustness, acrophase) were generated by wrist actigraphy-extended cosinor analysis. Incident PD cases were identified based on physician-diagnosed PD between 2005 and 2016. Logistic regression was used to determine the association between quartiles of rest-activity parameters and risk of incident PD.

Results

78 (2.7%) men developed PD during 11 years of follow-up. The risk of PD increased with decreasing circadian amplitude (strength of the rhythm), mesor (mean level of activity) or robustness (how closely activity follows a cosine 24h pattern); p for trend across quartiles &lt;0.05. After accounting for demographics, clinic site, education, depressive symptoms, body mass index, physical activity, benzodiazepine use, alcohol, caffeine, smoking, comorbidities and baseline cognition, those in the lowest quartile of amplitude, mesor or robustness had approximately three times the risk of developing PD compared to those in the highest quartile of amplitude [ORs (95% CI)= 3.11 (1.54-6.29)], mesor [3.04 (1.54-6.01)] and robustness [2.65 (1.24-5.66)]. The association remained after further adjustment for nighttime sleep disturbances and sleep duration. These associations were somewhat attenuated, but the pattern remained similar after excluding PD cases developed within 2 years after baseline. Acrophase was not significantly associated with risk of PD.

Conclusion

Older men with reduced circadian rhythmicity had an increased risk of incident PD over 11 years. Circadian disruption in the elderly may represent an important prodrome or risk factor for PD. Randomized trials should evaluate whether strategies to improve circadian function impact risk of PD.

Support

This work was supported by the NIA, NIAMS, NCATS, NIH Roadmap for Medical Research and the NHLBI under the grant numbers: U01AG027810, U01AG042124, U01AG042139, U01AG042140, U01AG042143, U01AG042145, U01AG042168, U01AR066160, UL1TR000128, R01HL071194, R01HL070848, R01HL070847, R01HL070842, R01HL070841, R01HL070837, R01HL070838, and R01HL070839.

1135 Longer And More Frequent Naps Predict Incident Alzheimer’s Dementia In Community-based Older Adults

Introduction

Excessive napping duration has been associated with cognitive decline. The effect of napping frequency is less understood, and little is known about the development of Alzheimer’s dementia associated with napping. We tested whether longer or more frequent naps in the elderly are linked to the development of incident Alzheimer’s dementia.

Methods

We studied 1,180 older adults (age: 81.0±7.3 [SD]) in the Rush Memory and Aging Project who have been followed for up to 14 years. Motor activities of up to 10 days were recorded at baseline to assess napping characteristics objectively. We defined daytime napping episodes as motor activity segments between 10AM and 7PM with continuous zero-activity for ≥10min but &lt;1h (to avoid off-wrist periods). Segments that were &lt;5min apart were merged. Alzheimer’s dementia diagnosis was determined using the criteria of the National Institute of Neurological and Communicative Disorders and Strone and the Alzheimer’s Disease and Related Disorders Association. Cox proportional hazards models were performed to examine the associations of daily napping duration and frequency with incident AD.

Results

Of 1,180 non-demented participants at baseline (including 264 with mild cognitive impairment), 277 developed Alzheimer’s dementia within 5.74±3.36 years. On average, participants napped for 38.3±1.0 (SE) min and1.56±0.04 (SE) times per day at baseline. After adjustment for age, sex, and education, every 30-min increase in daily napping duration was associated with a 20% increase in the risk of incident AD (95% confidence interval [CI]: 9%-31%; p=0.0002). One more nap per day was associated with a 19% increase in the risk of AD (95% CI: 8%-30%; p=0.0003). These associations remained after further adjustment for total sleep time.

Conclusion

Longer and more frequent daytime naps predict a higher risk of incident Alzheimer’s dementia. Future studies are needed to examine specific underlying mechanisms.

Support

This work was supported by NIH grants RF1AG064312, RF1AG059867, R01AG017917, and R01AG56352.

1152 Genetic Risk Of Alzheimer’S Disease Is Linked To Short Sleep Duration

Introduction

Sleep disturbances including short sleep duration are common in older adults, especially in those with Alzheimer’s disease (AD). However, it is unclear to what extent sleep duration is a manifestation of AD disease process. We examined whether genetic variants related to AD influence sleep duration in middle-aged and older adults and estimated the causal effects of AD on sleep duration using a mendelian randomization (MR) analysis.

Methods

We examined 406,687 UK Biobank participants with Caucasian genetic ancestry who self-reported sleep duration at baseline (2006-2010). Sleep duration was assessed by asking: “About how many hours sleep do you get in every 24 hours? (please include naps).” A genetic risk score for AD (AD-GRS) was calculated as a weighted sum of 23 previously identified AD-related single nucleotide polymorphisms in individuals of European ancestry. We evaluated whether AD-GRS predicted sleep duration using linear regression, adjusting for age, sex and principle components for genetic ancestry. We also stratified the analysis by age at baseline (≤55y or &gt;55y) and conducted a MR analysis to estimate the effect of AD (ICD-9/10 codes for AD/dementia diagnosis) on sleep duration.

Results

The participants (aged 56.91±8.00y) had an average sleep duration of 7.2 (Standard deviation [SD]=1.1) hours and AD-GRS of 0.11 (SD=0.40) (range: -1.15~1.85). Higher AD-GRS score predicted shorter sleep duration (b= -0.013, 95%CI:-0.022,-0.005), mainly among those aged over 55y (b= -0.023, 95%CI:-0.034,-0.012) and not in those 55y or younger (b= 0.006, 95%CI:-0.012,0.013); p for interaction by age=0.02. MR analysis using AD-GRS as an instrumental variable suggested that AD was associated with 1.76 hrs (b=-1.76, -2.62~ -0.90) shorter sleep duration in those aged &gt;55y.

Conclusion

Using a novel analytical approach, we found that higher genetic risk for AD predicted shorter sleep duration among older adults. This suggests shared genetic pathways; the biologic processes that lead to AD may also affect sleep duration.

Support

Dr. Leng received support from the National Institute on Aging (NIA) 1K99AG056598, and from GBHI, Alzheimer’s Association, and Alzheimer’s Society (GBHI ALZ UK-19-591141).

Self-assembled colloidal gold superparticles to enhance the sensitivity of lateral flow immunoassays with sandwich format

Background: Traditional lateral flow immunoassay (LFIA) based on 20-40 nm gold nanoparticles (AuNPs) as signal reporter always suffers from relatively low detection sensitivity due to its insufficient brightness, severely restricting its wide-ranging application in the detection of target analytes with trace concentration.

Methods: To address this problem, the self-assembled colloidal gold superparticles (GSPs) were synthesized as an improved absorption-dominated labeling probe for improving the sensitivity of sandwich LFIA. Five kinds of GSPs with the size ranging from 100 nm to 400 nm were synthesized by embedding hydrophobic AuNPs of size 12 nm as building blocks into the polymer nanobeads. The as-prepared GSPs were suggested as novel labeling probes of LFIA. The effects of the size of assembled GSPs on the sensitivity of sandwich LFIA was assessed, and the detection performance of GSPs-LFIA was further compared with traditional AuNPs-LFIA.

Results: The resultant GSPs showed extremely high light absorption but very low light scattering, which favor the absorption-dominated signal output in LFIA. Among them, the GSP₂₇₀-LFIA (size 270 nm) exhibits the highest sensitivity for human chorionic gonadotropin and hepatitis B surface antigen detection in real serum sample, which are approximate 39.79- and 13.8-fold higher than that of traditional AuNP₄₀-LFIA.

Conclusions: The proposed research demonstrated that the current GSPs can provide an ultrasensitive and quantitative detection for disease biomarkers in real serum samples as promising reporters of sandwich LFIA platform.

Core-Shell-Heterostructured Magnetic-Plasmonic Nanoassemblies with Highly Retained Magnetic-Plasmonic Activities for Ultrasensitive Bioanalysis in Complex Matrix

Herein, a facile self-assembly strategy for coassembling oleic acid-coated iron oxide nanoparticles (OC-IONPs) with oleylamine-coated gold nanoparticles (OA-AuNPs) to form colloidal magnetic-plasmonic nanoassemblies (MPNAs) is reported. The resultant MPNAs exhibit a typical core-shell heterostructure comprising aggregated OA-AuNPs as a plasmonic core surrounded by an assembled magnetic shell of OC-IONPs. Owing to the high loading of OA-AuNPs and reasonable spatial distribution of OC-IONPs, the resultant MPNAs exhibit highly retained magnetic-plasmonic activities simultaneously. Using the intrinsic dual functionality of MPNAs as a magnetic separator and a plasmonic signal transducer, it is demonstrated that the assembled MPNAs can achieve the simultaneous magnetic manipulation and optical detection on the lateral flow immunoassay platform after surface functionalization with recognition molecules. In conclusion, the core-shell-heterostructured MPNAs can serve as a nanoanalytical platform for the separation and concentration of target compounds from complex biological samples using magnetic properties and simultaneous optical sensing using plasmonic properties.

Amphiphilic ligand modified gold nanocarriers to amplify lanthanide loading for ultrasensitive DELFIA detection ofCronobacter

Thiolated ethylenediaminetetraacetic acid and thiolated acylhydrazine-terminated ligands modified gold nanoflowers as amplified nanocarriers to increase the Ln³⁺labeling ratio for improving the sensitivity of traditional DELFIA.

Supramolecular Recognition-Mediated Layer-by-Layer Self-Assembled Gold Nanoparticles for Customized Sensitivity in Paper-Based Strip Nanobiosensors

Herein, a smart supramolecular self-assembly-mediated signal amplification strategy is developed on a paper-based nanobiosensor to achieve the sensitive and customized detection of biomarkers. The host-guest recognition between β-cyclodextrin-coated gold nanoparticles (AuNPs) and 1-adamantane acetic acid or tetrakis(4-carboxyphenyl)porphyrin is designed and applied to the layer-by-layer self-assembly of AuNPs at the test area of the strip. Thus, the amplified platform exhibits a high sensitivity with a detection limit at subattogram levels (approximately dozens of molecules per strip) and a wide dynamic range of concentration over seven orders of magnitude. The applicability and universality of this sensitive platform are demonstrated in clinically significant ranges to measure carcinoembryonic antigen and HIV-1 capsid p24 antigen in spiked serum and clinical samples. The customized biomarker detection ability for the on-demand needs of clinicians is further verified through cycle incubation-mediated controllable self-assembly. Collectively, the supramolecular self-assembly amplification method is suitable as a universal point-of-care diagnostic tool and can be readily adapted as a platform technology for the sensitive assay of many different target analytes.

Plasmonic ELISA based on DNA-directed gold nanoparticle growth for Cronobacter detection in powdered infant formula samples

The traditional gold nanoparticle (AuNP) growth-based plasmonic ELISA (pELISA) strictly and directly controlled by reducing reagents can achieve high sensitivity, but it remains fragile toward the surrounding environment. This work developed a sandwich pELISA for Cronobacter detection in powdered infant formula samples by mediating AuNP growth through DNA. In this assay, DNA adsorbed on the surface of gold nanoseeds guided the anisotropic crystal growth with hydroxylamine as a reducing reagent, and the catalase-hydrogen peroxide (Cat-H₂O₂) system was introduced to bridge the DNA-directed AuNP growth and pELISA, as such DNA can be cleaved into fragments by the hydroxyl radical generated from oxidation of H₂O₂ through Fenton reagents. Under optimized conditions, the proposed pELISA can qualitatively detect Cronobacter species (Cronobacter muytjensii ATCC 51329) by the naked eye with a cut-off limit of 3 × 10⁵ cfu/mL. This method also revealed a good linear range (3 × 10² to 3 × 10⁷ cfu/mL) for quantitative detection of C. muytjensii ATCC 51329 with a limit of detection of 1.6 × 10² cfu/mL, which is approximately 162.5 times lower than that of horseradish peroxidase-based conventional ELISA (2.6 × 10⁴ cfu/mL). By taking advantage of highly stable DNA-directed AuNP growth, the proposed method shows a good performance in powdered infant formula samples spiked with different concentrations of C. muytjensii ATCC 51329 with average recoveries ranging from 90.79 to 119.09% and coefficient of variation ranging from 4.24 to 9.55%. These values corresponded to an acceptable accuracy and precision for the proposed method. In brief, this work shows potential for screening other analytes in food safety, clinical diagnostics, and environmental monitoring.

Gold Nanoflower-Enhanced Dynamic Light Scattering Immunosensor for the Ultrasensitive No-Wash Detection of Escherichia coli O157:H7 in Milk

Gold nanoflowers (GNFs) exhibit stronger light scattering ability than gold nanospheres (GNSs) with the same diameter, thereby contributing to enhancing the sensitivity of the scattering-based sensing method. However, the application of GNFs in biosensors based on dynamic light scattering (DLS) has not been yet reported. Herein, we describe for the first time an improved no-wash immunosensor based on dynamic light scattering for the detection of Escherichia coli O157:H7 (E. coli O157:H7) in milk using GNFs for sensitive signal transduction. To achieve this goal, a thiolated amphiphilic carboxyl ligand was introduced to modify the GNF surface and improve solution stability and antibody functionalization. Several key factors that affect the detection sensitivity of our developed GNF_DLS immunosensor were systematically investigated. Under the optimal conditions, our proposed GNF_DLS immunosensor provided an excellent linear detection for E. coli O157:H7 within the range from 6 × 10⁰ to 6 × 10⁴ colony-forming units (CFU)/mL, with a limit of detection of 2.7 CFU/mL. Combined with our previously reported two-step large-volume immunomagnetic separation (IMS) method, the designed GNF_DLS immunosensor can sensitively, selectively, and accurately detect the presence of E. coli O157:H7 in pasteurized milk. The potential of our GNF_DLS method for monitoring the presence of a single bacterial cell in 1 mL of sample solution was also demonstrated. Overall, the developed GNF_DLS immunosensor can be used for the rapid and high-sensitivity determination of pathogenic bacteria and can be extended for the ultrasensitive no-wash detection of other trace analytes.

[Study on the relationship between smoking behavior and health literacy among grade 4-6 primary students in Shandong province]

Objective: To investigate the associations between smoking and literacy on health among 4-6 grade primary school students. Methods: A questionnaire survey was conducted to research on health literacy and smoking among 4-6 grade pupils in Shandong province, through a multi-stage stratified cluster random sampling method. Sociodemographic characteristics, health literacy level and smoking rate were collected from respondents. Binary logistic regression analysis was used to evaluate the association of smoking and health literacy. Results: A total of 9 240 questionnaires were distributed, with the rate of valid response as 99.7%. The current smoking rate of the students was 2.6%, on higher in boys (3.1%) than in girls (2.0%). 60.8% of 4-6 grade students were found to have adequate health literacy level. Levels of literacy health in both boy and girl school students appeared 56.7% and 64.9%, respectively. Results indicated that health literacy in smokers (14.4%) was lower than that in non-smokers (62.0%). Results from the binary logistic regression analysis showed that the independent influencing factors would include grade, father's education level, economic situation of the family, self-assessment on the school record and literacy on health (P<0.01). After controlling the other independent variables, the smoking rate was 8.62 (1/0.116) times in students with low literacy level on health, than those with high literacy level. Conclusions: Literacy on health was significantly associated with smoking in the 4-6 grade pupils of Shandong province.

Magnetic Quantum Dot Nanobead-Based Fluorescent Immunochromatographic Assay for the Highly Sensitive Detection of Aflatoxin B1 in Dark Soy Sauce

Herein, we synthesized bifunctional magnetic fluorescent beads (MFBs) with a distinct core/shell structure by encapsulating octadecylamine-coated CdSe/ZnS QDs (OC-QDs) and oleic acid-modified iron oxide nanoparticles (OA-IONPs) into two polymer matrixes with different hydrophobic properties. The OC-QDs and OA-IONPs were mainly distributed in the outer layer of MFBs. The resultant MFBs displayed ca. 226-fold stronger fluorescence emission relative to the corresponding OC-QDs and retained ca. 45.4% of the saturation magnetization of the OA-IONPs. The MFBs were used to purify and enrich aflatoxin B1 (AFB1) from dark soy sauce and then utilized as a fluorescent reporter of immunochromatographic assay (ICA) for the sensitive detection of AFB1. Under the optimal detection conditions, the MFB-based ICA (MFB-ICA) displayed a dynamic linear detection of AFB1 in sauce extract over the range of 5-150 pg/mL with a half maximal inhibitory concentration of 27 ± 3 pg/mL ( n = 3). The detection limits for AFB1 in sauce extract and real dark soy sauce were 3 and 51 pg/mL, respectively, which are considerably better than those of the previously reported fluorescent bead-based ICA methods. The analytical performance of the proposed MFB-ICA in terms of selectivity and accuracy was investigated by analyzing AFB1-spiked dark soy sauce samples. The reliability of the proposed method was further confirmed by ultraperformance liquid chromatography with fluorescence detection. With the combined advantages of QDs and IONPs, the resultant MFBs offer great potential as reporters of ICA for the sensitive detection of trace pollutants in complex matrix samples.

Integrated magneto-fluorescence nanobeads for ultrasensitive glycoprotein detection using antibody coupled boronate-affinity recognition

Herein, we report a novel magnet-mediated antibody-boronate sandwich-typed assay (ABSTA) strategy for the ultrasensitive, specific, rapid, and enzyme-free detection of glycoproteins in complex samples.

An amphiphilic-ligand-modified gold nanoflower probe for enhancing the stability of lateral flow immunoassays in dried distillers grains

An amphiphilic ligand-capped gold nanoflower (AuNF) was proposed as a novel lateral flow immunoassay (LFA) reporter for zearalenone (ZEN) detection in distillers dried grains solubles (DDGS).

Fluorescence ELISA based on glucose oxidase-mediated fluorescence quenching of quantum dots for highly sensitive detection of Hepatitis B

Herein, we present a novel sandwich fluorescence enzyme linked immunosorbent assay (ELISA) for highly sensitive detection of Hepatitis B virus surface antigen (HBsAg) based on glucose oxidase (GOx)-induced fluorescence quenching of mercaptopropionic acid-modified CdTe quantum dots (MPA-QDs). In this system, hydrogen peroxide (H₂O₂) sensitive MPA-QDs was used as a signal output, and glucose oxidase (GOx) was used as label which can generate H₂O₂ via catalytic oxidation of glucose. The proposed method showed dynamic linear detection of HBsAg both in the range of 47pgmL^-1 ~ 380pgmL^-1 and 0.75ngmL^-1 ~ 12.12ngmL^-1. The detection limit of the proposed fluorescence ELISA was 1.16pgmL^-1, which was approximately 430-fold lower than that of horseradish peroxidase (HRP)-based conventional ELISA. The average recoveries for HBsAg-spiked serum samples ranged from 98.0% to 126.8% with the relative standard derivation below 10%, thus indicating acceptable precision and high reproducibility of the proposed fluorescence ELISA for HBsAg detection. Additionally, the developed method showed no false positive results analyzing 35 real HBsAg-negative serum samples, and exhibited excellent agreement (R²=0.9907) with a commercial time-resolved fluorescence immunoassay (TRFIA) kit for detecting 31 HBsAg-positive serum samples. In summary, the proposed method based on fluorescence quenching of H₂O₂ sensitive QDs is considerably to be an excellent biodetection platform with ultrahigh sensitivity, good accuracy and excellent reliability.