Dual Detection Research Articles

Two dye-encapsulated triple-emitting naphthalene-based Zr-MOFs for tunable white-light emission and dual mode detection of inorganic ions

A dual-dyes-encapsulated white-light emitting naphthalene-based Zr-MOF was synthesized and employed as fluorescent sensor for detecting inorganic ions with quenching or colorimetric detection mode.

Sensing and slow light applications of graphene plasmonic terahertz structure

In this work, Ansys FDTD is used to design and simulate a terahertz metamaterial structure based on periodic continuous pattern graphene monolayer, and the high-quality PIT phenomena are obtained by continuously adjusting structural parameters. To validate the designed structure, the simulated transmission curve (reflection curve) obtained is compared with the theoretical transmission curve (reflection curve) derived from coupled-mode theory. It is observed that these two results exhibit a remarkably high degree of overlap. The resonant frequency and Fermi energy reveals a perfect linear correlation between them with the resonant frequency increasing proportionally with Fermi energy increasing. Dynamic tuning of PIT can be realized by adjusting the Fermi energy of graphene. For a more in-depth study of its sensing characteristics, the structure is placed in different environments. As the refractive index of the detection medium increases, the resonant frequency gradually decreases, demonstrating a redshift phenomenon. By manipulating the resonant frequency of the PIT sensor, the selective detection of specific target can berealized. After analyzing the sensitivity and FOM values of the structure, it is found that the maximum sensitivity is 1.457 THz/RIU. At a resonant frequency of 6.8174 THz, FOM reaches 30.5652. In summary, the sensor structure designed in this work has dual frequency sensing characteristics and can be used for dual frequency detection. Moreover, compared with other sensor structures, it demonstrates superior sensing performance. Additionally, in studying the slow light effect of the structure, it is found that as the Fermi energy increases, the group index and phase shift at the transparency window continue to increase. At the Fermi energy of 1.2 eV, the group index reaches a high value of 584. This is because in the PIT phenomenon, transparent peaks are formed due to multimodal coupling. This coupling will significantly improve the dispersion characteristics near the transparent peak, resulting in a large group index near the transparent peak. Furthermore, with the increase of carrier mobility, the group index and phase shift of the structure also gradually increase. At a carrier mobility of 0.75 m²/(V·s), the group refractive index is 456, and reaches 1010 at 2.0 m²/(V·s). In this study, the slow-light performance of graphene structure can be optimized through jointly adjusting the Fermi energy and carrier mobility. This research provides theoretical support and methods for designing advanced graphene-based sensors and devices for slow-light applications.

Dual Detection of Hepatitis B and C Viruses Using CRISPR‐Cas Systems and Lateral Flow Assay

The development of sensitive and specific diagnostic tools for hepatitis B virus (HBV) and hepatitis C virus (HCV) remains crucial for effective disease management and control. In this study, we utilized CRISPR‐Cas12 and CRISPR‐Cas13 systems for the detection of HBV (DNA virus) and HCV (RNA virus), respectively. We designed and tested multiple guide RNAs (gRNAs) targeting both viruses, confirming successful cleavage of target sequences through gel electrophoresis and a fluorescent reporter assay. Using optimized gRNAs, we developed a lateral flow assay (LFA) for sensitive detection of HBV and HCV, demonstrating a concentration‐dependent signal increase. Importantly, no cross‐reactivity was observed with other viral targets. To further enhance sensitivity, we employed a dual‐enzyme approach, combining Cas12 and Cas13 in a single reaction, which significantly improved detection limits for both viruses. Finally, we developed a dual antigen detection LFA strip capable of simultaneously detecting both HBV and HCV in a single sample. This approach holds promise for point‐of‐care (POC) diagnostics where the specific viral infection is unknown. This study addresses the current limitations in CRISPR‐Cas based diagnostics, namely, the need for ultrasensitive detection methods and the ability to detect multiple antigens using a single test strip. Our findings demonstrate the feasibility of using CRISPR‐Cas systems for highly sensitive and specific detection of HBV and HCV, paving the way for potential POC application.

Free-base amino acid-encoded microsystems for dual detection of narcotics and therapeutic antidote monitoring

Theranostics potential: Au nanocactuses as a novel SERS substrate and underlying polymeric Trp interface for drug release kinetics study.

Ca@Cu-CD nanoprobe for dual detection of glycine and ex vivo glycine imaging.

Hydrothermally prepared copper-doped carbon dots (Cu-CDs) were modified with Ca2+, which serve as an excellent platform for the recognition of glycine. The feeble emission of Ca@Cu-CD increases substantially in the presence of glycine due to aggregation-induced emission. At the same time, there was a 5-fold increase in the current response of the Ca@Cu-CD modified electrode as compared to the control. The exceptional combination of fluorescence and conducting properties, along with Ca-glycine interaction, establishes our probe as a dual sensor for the detection of glycine in real serum samples. The limit of detection for this nonenzymatic fluorescence and electrochemical sensing are 17.2 and 4.1 nM, respectively. Furthermore, an extensive evaluation of the toxicity and bioimaging properties in fruit fly Drosophila melanogaster shows that the Ca@Cu-CD probe is not cytotoxic and can be applied for ex vivo imaging of glycine.

Simultaneous Detection of Helicobacter pylori and Clarithromycin Resistance Mutations Using RAA-CRISPR/Cas13a Assay.

Infection caused by Helicobacter pylori (H. pylori) affects approximately 50% of the global population. It is a major pathogenic factor for chronic gastritis and gastric cancer. Besides, the resistance to antibiotics such as clarithromycin could reduce the eradication rate. Currently, there is an urgent need for a swift, easy to perform, and highly sensitive detection method for H. pylori and clarithromycin resistance. We used FAM/Digoxin labeled primers to amplify specific H. pylori 23S rRNA fragments by Recombinase Aided Amplification (RAA), and resistance mutations were distinguished using CRISPR/Cas13a system combined with lateral flow strip. Twenty-eight saliva samples were analyzed using qPCR, gene sequencing and this method to evaluate the detection efficiency. We developed a simultaneous detection method for H. pylori and clarithromycin resistance mutations named sensitive H. pylori easy-read dual detection (SHIELD). The results showed both A2142G and A2143G mutant DNAs causing clarithromycin resistance could be distinguished from the wild type with a concentration of 50 copies/μL, and no cross-reaction with other 5 common gastrointestinal bacteria was observed. For the detection of H. pylori in 28 saliva samples, the positive predictive value of this method was 100% (19/19) in comparison with qPCR. For detecting clarithromycin resistance, the positive predictive value of this method was 84.6% (11/13) compared with gene sequencing. SHIELD assay showed high sensitivity and specificity in detecting H. pylori and clarithromycin resistance mutations. It could be a potential measure in the rapid detection of H. pylori, large-scale screening and guiding clinical medication.

Hyper-Raman spectroscopy of biomolecules.

The hyper-Raman scattering (HRS) spectra of biologically significant molecules (D-glucose, L-alanine, L-arabinose, L-tartaric acid) in aqueous solutions are reported. The HRS spectra were measured using a picosecond laser at 532 nm operating at a MHz repetition rate. High signal to noise spectra were collected with a commercial spectrometer and CCD without resonant, nanoparticle, or surface enhancement. The HRS peak frequencies, relative intensities, band assignments, and depolarization ratios are examined. By comparing HRS to Raman scattering (RS) and infrared absorption spectra we verify that the IR-active vibrational modes of the target molecules are observed in HRS spectra but come with substantially different peak intensities. The HRS of the biomolecules as well as water, dimethyl sulfoxide, methanol, and ethanol were deposited into a data repository to support the development of theoretical descriptions of HRS for these molecules. Depositing the spectra in a repository also supports future dual detection RS, HRS microscopes which permit simultaneous high-spatial-resolution vibrational spectroscopy of IR-active and Raman-active vibrational modes.

A laser-induced graphene-based electrochemical immunosensor for nucleic acid methylation detection.

The detection of methylation in DNA and RNA is essential for the diagnosis and treatment of a wide range of diseases. A one-step fabricated laser-induced graphene (LIG) electrode has received increasing attention due to its good electrical conductivity, large specific surface area, ease of miniaturization, low cost and flexibility. Herein, a potential biosensor for N6-methyladenosine (m6A-RNA) and 5-methylcystosine-single strand DNA (5mC-ssDNA) detection was designed. The aim of this paper is to address the problem of detecting the m6A-RNA and 5mC-ssDNA content in cells. By stepwise modification of gold nanoparticles (AuNPs), sulfhydryl-modified nucleic acid chains, biotin-modified antibodies, and streptavidin-modified horseradish peroxidase (SA-HRP) at the LIG electrode, the peak current responses exhibited an increase proportional to the concentration of m6A-RNA and 5mC-ssDNA in the hydrogen peroxide-hydroquinone (H2O2-HQ) system. This method demonstrated a low detection limit of 2.81 pM for m6A-RNA and 9.53 pM for 5mC-ssDNA, with a linear detection range of 0.01 nM to 10 nM for both targets. The regression equation was determined as ΔI = 4.83 log c + 12.32 (R2 = 0.9980) for m6A-RNA and ΔI = 9.82 log c + 22.09 (R2 = 0.9903) for 5mC-ssDNA. Our method has good selectivity toward different detection targets of nucleic acid chains, stability for long-term storage and consecutive scanning (RSD of 9.42% and 2.08%, respectively) and reproducibility of 5 electrodes (RSD of 6.85%). This method utilizes gold-sulfur bonding to immobilize the detection target, which improves the conductivity of the LIG electrode and introduces an amplified portion of the signal by taking advantage of antigen-antibody specific binding. Thus, dual detection of m6A-RNA and 5mC-ssDNA was realized. Importantly, this approach is successfully applied for the detection of targets in spiked samples extracted from HeLa cells, suggesting its potential for clinical applications and providing a new perspective for the development of point-of care testing (POCT) techniques.

DroidExaminer: An Android Malware Hybrid Detection System Based on Ensemble Learning

<p>Android is an open-source mobile operating system, with more than 70% of the mobile market share, widely popular on various intelligent devices. At the same time, the number of new malicious applications keeps increasing every year. In this paper, we first discuss the advantages and disadvantages of various detection methods for malicious software. A single detection method can only cover specific types of malware. Therefore, we propose a system that combines static structural analysis and dynamic detection of malware. This system has dual detection capability, which consists of a client and a server. The client is a lightweight Android application that is used to obtain the relevant data information of the installation package. The server is responsible for static analysis of APK and dynamic running of monitoring logs to get the relevant feature information. Based on the feature information, the Bagging algorithm of ensemble learning is adopted, and the decision tree and random forest are combined to identify the malware accurately. We collected 4210 Android software samples, with malicious apps accounting for about 20% of the total. Cross-testing of malware detection on this sample set showed that DroidExaminer achieved approximately 96% accuracy in detecting malware. It can resist confusion and conversion techniques, and the test performance overhead is less. In addition, DroidExaminer can alert the user to the details of malware intrusion so that the user can prevent malware intrusion.</p> <p> </p>

Disposable paper-based screen-printed electrochemical immunoplatform for dual detection of esophageal cancer biomarkers in patients' serum samples

A schematic illustration of the fabrication of disposable paper-based screen-printed electrochemical immunoplatforms for dual detection of esophageal cancer biomarkers in patient serum samples.

Ultra-low dual detection of tetrahydrocannabinol and cannabidiol in saliva based on electrochemical sensing and machine learning: overcoming cross-interferences and saliva-to-saliva variations

Detection of tetrahydrocannabinol and cannabidiol in saliva using m-Z-THC and m-Z-CBD electrochemical sensors and machine learning as a powerful tool to overcome cross-interferences and saliva-to-saliva variations.

A highly effective peroxidase-mimic nanozyme of S, N-carbon dot-decorated cerium organic framework-based colorimetric detection of Hg2+ ion and thiophanate methyl.

In this study, we proposed a colorimetric probe as S, N-carbon dot-decorated Ce-MOF (S, N-CD@Ce-MOF) for the dual detection of mercury and thiophanate methyl (TM), which are simultaneously present pollutants in the environment and foodstuffs. These pollutants cause serious threats to human health, such as carcinogenicity and neurovirulence. Herein, we synthesized S, N-CD@Ce-MOF using the hydrothermal method and applied it to a "turn-off-on" probe to detect mercury and TM using the colorimetric method in water and food samples. S, N-CD@Ce-MOF shows excellent peroxidase activity by catalyzing the chromogenic substrate of 3,3',5,5'-tetramethylbenzidine (TMB), resulting in deep blue-colored oxidized TMB product (ox TMB) in the presence of H2O2 with a UV absorption wavelength at 654 nm. However, the addition of Hg(II) ions prohibits the oxidation of TMB by an electron transfer effect and easily binds with -S, -N-containing sites on the surface of carbon dots, obstructing the catalytic active sites and decreasing catalytic efficiency with weak UV absorption at 654 nm as a "turn-off". Subsequently, the addition of TM to the above sensing solution as a "turn-on" was triggered by the TM-Hg complex formation and permitted TMB oxidation with a strong absorption peak at 654 nm. Furthermore, this proposed sensor demonstrates a superior linear response to mercury ions and TM in the ranges from 0 to 15 μM and 0 to 14 μM, respectively. The developed colorimetric assay exhibits good sensitivity and selectivity against various possible interferences. Furthermore, we found that the limits of detection for Hg2+ and TM were as low as 0.01 μM and 0.03 μM, respectively. The developed sensor provides various benefits, such as cost-effectiveness, simplicity without a complex detection process, and naked-eye detection. Consequently, our proposed colorimetric technique worked well for the detection of Hg2+ in real water samples and TM in real apple and tomato juice.

Pen direct writing of SERRS-based lateral flow assays for detection of penicillin G in milk.

Direct pen writing offers versatile opportunities for development of low-cost tests for point-of-care applications. In this work a lateral flow immunoassay (LFIA) test was fabricated by hand "writing" immunoprobes onto hand-cut nitrocellulose strips with a commercial fountain pen. The qualitative capabilities of the test were extended by addition of a Raman reporter and consequent design and fabrication of a Surface Enhanced Resonant Raman Scattering (SERRS)-LFIA test. As proof-of-concept, dual detection of penicillin G was achieved in milk with a visual LOD of 20 ppm and a dynamic range of 0.03-97.5 ppm. Evaluation against equivalent tests performed with conventionally prepared LFIA strips showed comparable results, thus demonstrating the validity of the test. These results demonstrate the potential for further decrease in cost and consequent broader use of LFIA tests in remote regions and resource-limited environments.

A novel coupling technique based on thermal desorption gas chromatography with mass spectrometry and ion mobility spectrometry for breath analysis

Exhaled breath analysis is evolving into an increasingly important non-invasive diagnostic tool. Volatile organic compounds (VOCs) in breath contain information about health status and are promising biomarkers for several diseases, including respiratory infections caused by bacteria. To monitor the composition of VOCs in breath or the emission of VOCs from bacteria, sensitive analytical techniques are required. Next to mass spectrometry, ion mobility spectrometry (IMS) is considered a promising analytical tool for detecting gaseous analytes in the parts per billion by volume to parts per trillion by volume range. This work presents a new, dual coupling of thermal desorption gas chromatography to a quadrupole mass spectrometer (MS) and an IMS by operating a simple splitter. Nearly identical retention times can be reached in the range of up to 30 min with slight deviations of 0.06 min–0.24 min. This enables the identification of unknown compounds in the IMS chromatogram using unambiguous mass spectral identification, as there are still no commercially available databases for IMS. It is also possible to discriminate one of the detectors using the splitter to improve detection limits. Using a test liquid mixture of seven ketones, namely 2-butanone, 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone, 2-nonanone, and 2-decanone with a concentration of 0.01 g l−1 reproducibilities ranging from 3.0% to 7.6% for MS and 2.2%–5.3%, for IMS were obtained, respectively. In order to test the system optimized here for the field of breath analysis, characteristic VOCs such as ethanol, isoprene, acetone, 2-propanol, and 1-propanol were successfully identified in exhaled air using the dual detector system due to the match of the corresponding IMS, and MS spectra. The presented results may be considered to be a starting point for the greater use of IMS in combination with MS within the medical field.

LncRNA-mir3471-limd1 regulatory network plays critical roles in HIBD.

The purpose of this study was to identify the target genes of tcon_00044595, elucidate its activation site, and provide novel insights into the pathogenesis and treatment of neonatal hypoxic-ischemic brain damage (HIBD). Through homologous blast analysis, we identified predicted target sequences in the neighboring regions of the long non-coding RNA (lncRNA) tcon_00044595, suggesting that limd1 is its target gene. Starbase was utilized to identify potential candidate microRNAs associated with the lncRNA. The interaction between the candidate microRNAs and limd1 was investigated and validated using various experimental methods including in vitro cell culture, cell transfection, dual fluorescence reporter detection system, and real-time PCR. Homology alignment analysis revealed that the lncRNA tcon_00044595 exhibited a 246bp homologous sequence at the 3' end of the adjacent limd1 gene, with a conservation rate of 68%. Analysis conducted on Starbase online identified three potential microRNA candidates: miR-3471, miR-883a-5p, and miR-214-3p. Intracellular expression of the limd1 gene was significantly down-regulated upon transfection with miR-3471, while the other two microRNAs did not produce noticeable effects. Luciferase reporter assays identified two interaction sites (UTR-1, UTR-2) between miR-3471 and the limd1 3'UTR, with UTR-1 exhibiting a strong influence. Further CCK8 assay indicated a protective role of miR-3471 during low oxygen stroke in HIBD. The potential regulatory relationship between lncRNA (tcon_00044595), miR-3471, and the target gene limd1 suggests their involvement in the occurrence and development of HIBD, providing new insights for investigating the underlying mechanisms and exploring targeted therapeutic approaches for HIBD.

Dual optical detection approach for capillary electrophoresis following two-step liquid-liquid extraction to determine ten phenols in water samples

In this research, the analytical method was developed and evaluated for determining phenol and its nine derivatives belong to the US EPA priority pollutant list in water samples by using dual-channeled capillary electrophoresis (CE) coupled with two types of optical detectors, namely LED-induced fluorescence (LEDIF) and ultraviolet (UV) detectors. The optimal background electrolytes for the first and second CE channels were 20 mM borate (pH 9.80) with 400 µM fluorescein and 55 mM borate (pH 11.75), respectively. The two-step liquid-liquid extraction (LLE) was used for sample preparation and enrichment, in which phenol and its derivatives were extracted from the aqueous phase using 10 mL of n-hexane/1-octanol (60/40, v/v) and then were back extracted into a 0.1 M NaOH as a final acceptor phase. Under the optimal CE and two-step LLE conditions, the enrichment factors of 10 phenols were 184 – 1120-fold, and the method detection limits were lowered to 0.02–0.60 µg/L. The obtained intra-day and inter-day precisions in terms of relative standard deviations (RSD) were between 4.0 and 7.3 % and 6.7 and 14 %, respectively. This approach was used to determine phenols in water samples, with recoveries ranging from 82.0 to 108.9 %. In combination with sample enrichment by two-step LLE extraction, this is the first CE study conducted to determine phenols in the EPA list using two detector approaches, specifically CE-LEDIF/CE-UV.

Folic Acid-Conjugated Fe-Au-Based Nanoparticles for Dual Detection of Breast Cancer Cells by Magnetic Resonance Imaging and Computed Tomography

Purpose: We synthesized folic acid-conjugated Fe3O4/Au-pralidoxime chloride Nanoparticles (Fe2O3/Au@PAM NPs) for use as dual-modal contrast agents for Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) in the diagnosis of breast cancer.
 Materials and Methods: Fe2O3/Au@PAM NPs labeled or not to folic acid were synthesized and analyzed by dynamic light scattering, transmission electron microscopy, and vibrating sample magnetometry. The ability of these NPs to create image contrast was also investigated in silico and in vitro (in MCF-7 breast cancer cells and A549 lung cancer cells) with CT and MRI.
 Results: Dynamic light scattering and transmission electron microscopy revealed that the Fe2O3/Au@PAM NPs were nearly spherical. The average diameter of Fe2O3/Au NPs increased from 11.6 nm to 98 nm after folic acid conjugation. The saturation magnetization values of Fe2O3/Au@PAM NPs with and without folic acid conjugation were 25.56 and 32.6 emu/g, respectively. Conjugation of folic acid to NPs greatly improved their uptake by cancer cells. The additional coating of NPs with FA reduced the T2 relaxation time and signal intensity for MRI. Folic acid-labeled MCF-7 cells had a radiodensity measurement of 208 Hunsfield Units (HU) compared to 95 HU for A549 cells. For breast cancer cells, NPs labeled with folic acid significantly improved the X-ray absorption coefficient as a sign of active cellular uptake compared to NPs without labeling.
 Conclusion: Folic acid-labeled Fe2O3/Au@PAM NPs can serve as dual CT/MRI contrast agents and improve the sensitivities of both modalities for the detection of cancer cells.

Research on Pedestrian Detection Based on Multimodal Infor-mation Fusion

Aiming at the matter that pedestrian detection in the autonomous driving system is vulnerable to the influence of the external environment and the detector supported single sensor modal detector has poor performance beneath the condition of enormous amendment of unrestricted light-weight, this paper proposes a fusion of light and thermal infrared dual mode pedestrian detection methodology. Firstly, 1 × 1 convolution and expanded convolution square measure are introduced within the residual network, and also the ROI Align methodology is employed to exchange the ROI Pooling method-ology to map the candidate box to the feature layer to optimize the Faster R-CNN. Secondly, the loss performance of the generalized intersection over union (GIoU) is employed because of the loss performance of the prediction box positioning regression; finally, supported by the improved Faster R-CNN, four forms of multimodal neural network structures square measure designed to fuse visible and thermal infrared pictures. According to experimental findings, the proposed technique outperforms current mainstream detection algorithms on the KAIST dataset. As compared to the conventional ACF + T + THOG pedestrian detector, the AP is 8.38 percentage points greater. Compared to the visible light pedestrian detector, the miss rate is 5.34 percentage points lower.

High-performance liquid chromatography analysis of alkaloids in various parts of lotus extracts with ion mobility spectrometry and mass spectrometry dual detection.

Using high-performance liquid chromatography coupled with electrospray ionization-ion mobility spectrometry and mass spectrometry, we proposed a dual-detection method for the identification and profiling of alkaloids in various lotus parts including leaf, plumule, stem, seed epicarp, and receptacle. The eluent from high-performance liquid chromatography was split and conducted to electrospray ionization-ion mobility spectrometry and time-of-flight mass spectrometry separately to facilitate the compound identification. In total, 23 kinds of alkaloids were identified based on m/z, drift time, and retention time, including alkaloid isomers such as lirinidine, N-nornuciferine, and O-nornuciferine with identical m/z that are difficult to differentiate using mass spectrometry alone. Using this method, we investigated the changing dynamics of alkaloid accumulation in lotus leaves and lotus stems at different harvesting periods. The total alkaloid content showed an increasing trend with the growth and development of leave and stem. Overall, the developed dual detection method has the advantages of high peak capacity and high sensitivity compared with the conventional detection method and facilitates the identification of detected compounds.

Eosin Y embedded Gd-MOF as a dual emission detection platform for dopamine

A 2D Gd-MOF {Gd-MOF = [Gd(L)(NO3) (DMF)2]n (H2L = 2,5-Bis(1,2,4-triazol-1-yl) terephthalic acid, DMF = N, N-dimethylformamide)} was synthesized based on solvothermal method. To achieve double emission peaks, Eosin Y embedded Gd-MOF (EY@Gd-MOF) was prepared through the synthetic encapsulating method. Due to the effective FRET between EY and Gd-MOF, EY@Gd-MOF shows double emission characteristic peaks. The ratio of emission peaks is used as the detection signal to replace the absolute fluorescence intensity of emission peak, and EY@Gd-MOF as a self-calibrated fluorescence sensor to detect dopamine, which realizes the selective detection of dopamine. Under optimal conditions of pH = 9, dopamine polymerizes to produce polydopamine, which attaches to the surface of EY@Gd-MOF and completely quenches the fluorescence of EY@Gd-MOF and the detection limit for dopamine is 0.124 μM. Because the excitation spectrum of Gd-MOF fully covers the ultraviolet absorption spectrum of polydopamine, energy competitive absorption is the major cause of fluorescence quenching. In addition, EY@Gd-MOF can be made into a test strip to detect dopamine, and also has the ability to detect in synthetic urine, providing a feasible scheme for the actual detection of dopamine.