Short Detection Time Research Articles

Lateral Flow Immunoassay for the Rapid Detection of Thiamethoxam in Tea Based on a SERS Tag Constructed by Phenolic-Mediated Coating Engineering.

Sensitive and accurate detection of thiamethoxam in tea is significant to ensuring consumer health. In this study, surface-enhanced Raman scattering (SERS) tags were prepared by using a polyphenol-mediated coating engineering strategy. This approach involved the self-assembly of tannic acid (TA) and self-polymerization of benzene-1,4-dithiol (BDT) on the surface of gold nanoparticles, resulting in the formation of Au@pBDT-TA. The SERS tags possess high Raman signals and antibody adsorption properties, avoiding the complex decoration or label steps of SERS reporters. We discovered that Au@pBDT-TA, composed of gold nanoparticles at 40 nm and a pBDT-TA thickness of 10 nm, was optimal for the development of the SERS lateral flow immunoassay (LFIA). In comparison to the gold nanoparticle-based LFIA, the SERS-LFIA demonstrated 4-fold and 720-fold enhancements in visual and quantitative limits of detection in buffer solution. The SERS-LFIA demonstrated quantitative limits of detection of 0.06 and 0.1 ng/g for black and green tea, respectively, with a broader linear range spanning over 2 orders of magnitude and a short detection time of 20 min. The proposed SERS-LFIA not only offers a sensitive and reliable method for monitoring thiamethoxam in tea but also possesses a versatile potential that can be easily adapted for the trace detection of various other targets.

Ship detection method based on attention guidance and multi-sample decision making

Single-stage target detection methods have the characteristics of fast training speed and short detection time. However, its feature pyramid network is difficult to suppress the background and noise information of SAR ship images, and the detection head has prediction errors. To address this problem, this paper proposes a detection model based on attention guidance and multi-sample decision for synthetic aperture radar ship detection. Firstly, an attention guidance network is proposed and added to the highest level of the feature pyramid to suppress background and noise interference, thereby improving the representation ability of features. Secondly, a multi-sample decision network is proposed to participate in the prediction of target position. This network alleviates the impact of prediction errors on detection results by increasing the number of samples output in the regression branch. Finally, a novel maximum likelihood loss function is designed. This loss function constructs a maximum likelihood function using the samples output from the multi-sample decision network, which is used to standardize the training of the decision network and further improve the accuracy of target positioning. Taking the RetinaNet network model as the baseline method, compared with the baseline method and the current advanced target detection methods, this method shows the highest detection accuracy on the ship detection dataset SSDD, with AP reaching 52.8%. Compared with the baseline method, the proposed method improves the AP evaluation index 3.4% ∼ 5.7%, and the training parameter Params only increases by 2.03 M, and the frame rate FPS only decreases 0.5Iter/s.

Detection of carbapenem-resistant gram-negative bacilli in Japan using the fully automated bacterial testing device RAISUS S4

ObjectiveWe investigated a rapid detection method for carbapenemase-producing gram-negative bacilli (CP-GNR) using meropenem (MEPM) to assess the efficiency of the antimicrobial susceptibility testing. MethodsWe used the function that can monitor the growth curve with the resistant bacteria monitoring function (RAISUS S4). Rapid detection of CP-GNR was performed using RAISUS S4 in two types of antimicrobial susceptibility testing, the RAISUS 18-hour method (18-h method) and RAISUS rapid method (rapid method) for Enterobacterales (F-GNR) and non-fermenting Gram-negative bacilli (NF-GNR). ResultsWhen F-GNR were based on MEPM MIC ≥ 0.25 μg/mL, CP-GNR were detected with a sensitivity of 100% (58/58) for the 18-h method and 98.3% (57/58) for the rapid method; the shortest detection times were 5.3 and 4.0 h, respectively. When NF-GNR were based on MEPM MIC > 8 μg/mL, it was possible to detect CP-GNR with 100% sensitivity (58/58) in both methods. Furthermore, in the analysis using the 18-h method for monitoring resistant bacteria, when ≥ 2 µg/mL was used as the screening concentration for F-GNR, approximately 50% of the resistant genotypes, NDM, GES, and KPC, were detected in approximately 7 h. However, detecting the IMP and VIM took 11–12 h. ConclusionsThe 18-h and rapid methods with RAISUS S4 were highly correlated with the results of the microdilution method of CLSI, and CP-GNR detection was rapid using a function that can monitor the growth curve with RAISUS S4.

An RPA-Based CRISPR/Cas12a Assay in Combination with a Lateral Flow Assay for the Rapid Detection of Shigella flexneri in Food Samples.

Among the pathogens that cause infectious diarrhea in China, Shigella is the most prominent. Shigellosis affects both adults and children, particularly those in developing nations, with nearly 190 million annual cases and a third resulting in fatalities. The recently emerged CRISPR/Cas system has also been increasingly applied for the detection of different biological targets. The lateral flow assay (LFA) has the advantages of short detection time, simple operation, high sensitivity, and low cost, and it provides an ideal platform for on-site detection. In this study, a recombinase polymerase amplification-CRISPR/Cas12a-LFA test for Shigella flexneri was constructed. The established method had good specificity and sensitivity, and the qualitative accuracy of 32 tested strains reached 100%. The detection limit of genomic DNA reached 8.3 copies/μL. With the advantages of high accuracy and portability, this diagnostic apparatus represents a novel method of identification and detection of Shigella flexneri, particularly in settings that lack complex laboratory infrastructure.

Rapid identification of milk powder adulteration based on surface-enhanced Raman spectroscopy

In recent years, milk powder adulteration has emerged as a matter of great concern. In this study, a rapid, accurate, and efficient detection method based on surface-enhanced Raman spectroscopy (SERS) combined with principal component analysis (PCA) was established to detect milk powder adulteration. The “coffee ring” effect-based gold nanoparticles (Au NPs) as the SERS-enhancing substrate were coupled with a portable Raman spectrometer, which enabled the differentiation of various brands of milk powder and the detection of melamine in milk powder. The substrate exhibited good SERS enhancement ability with an enhancement factor of 104. Furthermore, a strong linear correlation with a correlation coefficient (R2) of 0.9903 was observed between the melamine Raman intensity and concentration from 0.5 to 5.0 mg/kg. The calculated limit of detection of melamine (LOD) was 0.15 mg/kg, while the limit of quantitation (LOQ) was 0.5 mg/kg. In addition, when the method was applied to the detection of melamine in milk powder samples, this method achieved the recovery rates of melamine in milk powder samples ranged from 92.83% to 98.86% with relative standard deviations between 0.84% and 1.14%. In summary, the established method offers the advantages of cost-effectiveness, less sample requirement, and shorter detection time, meeting the needs for milk powder classification and rapid melamine detection.

Rapid distance estimation of odor sources by electronic nose with multi-sensor fusion based on spiking neural network

The inference of odor source locations holds great potential value in chemical leak detection, explosive searches and flammable substance detection. Sensor response and derivative changes are common indicators used to estimate source distance. However, most studies often rely on single-feature methods using a single sensor. In this study, a novel distance indicator based on a spiking neural network (SNN) that integrates multiple sensors is proposed. SNN was introduced for effective multi-sensor data fusion, which can provide accurate and rapid source distance estimation. The indicator's accuracy and quick detection capabilities were tested using a publicly available wind tunnel dataset and compared with single-sensor indicators. Additionally, an olfactory robot platform was constructed to test the method's real-time performance. Results demonstrate that this method effectively utilizes sensor arrays to estimate source distance, with an average root mean square error (RMSE) of less than 0.1 m across different wind speeds, outperforming single-sensor-based indicators. Additionally, the model exhibits good distance estimation performance within a relatively short detection time, with an average RMSE of 0.118 m. Practical testing on a mobile robot platform confirms the applicability of this distance indicator for real-time distance monitoring. In conclusion, the proposed distance indicator enables effective distance estimation for odor sources, providing a promising method for odor source localization and olfactory navigation.

Monitoring of ketamine-based emerging contaminants in wastewater: a direct-injection method and fragmentation pathway study

The ketamine (KET) and its analogs consumed by humans are becoming emerging contaminants (ECs), as they at present in surface waters after being carried through wastewater systems. Drugs in wastewater can be analyzed using the direct-injection method, a simple wastewater analysis (WWA) method that can provide objective, continuous and nearly to real-time findings. This article describes an ultra-high-pressure liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for the simultaneous quantification and confirmation of seven KET-based ECs in wastewater by direct injection. After optimization of the UPLC–MS/MS and sample pretreatment conditions, the method was validated and applied to samples (n = 157) collected from several wastewater treatment plants (WWTPs) in southern China in which KET had the highest detection rate. The established direct-injection method was not only simple to perform but also had better sensitivity, shorter detection times, and analyzed more KET-based ECs than currently published methods, meeting the requirements for the monitoring and high-throughput analysis of common KET-based ECs. We also analyzed the fragmentation pathway of KET-based ECs to obtain product ion information on other unknown substances. Additional studies are needed to establish a comprehensive direct-injection screening method of ECs in wastewater on model-based assessment.

Establishment of a Rapid Detection Method for Highly Virulent Klebsiella Pneumoniae Based on Multienzyme Isothermal Rapid Amplification Technology.

This study aimed to establish a method for the rapid detection of highly virulent Klebsiella pneumoniae (hvKP) by using multienzyme isothermal rapid amplification (MIRA) technology. The laboratory can quickly, accurately, and conveniently diagnose highly virulent Klebsiella pneumoniae infection. For this study, 7 laboratory standard strains and 184 clinical isolates (including 70 strains of Klebsiella pneumoniae) were collected and screened for highly virulent Klebsiella pneumoniae based on its colony morphology, wire drawing test, and next-generation sequencing (NGS) results. Based on the nucleic acid sequence of the peg344 gene of highly virulent Klebsiella pneumoniae on GenBank (no. AP006726.1), specific conserved regions were selected to design MIRA and real-time fluorescence quantitative PCR (qPCR) specific primers and probes. The MIRA and qPCR methods were used to detect the tested strain, and the specificity, sensitivity, and clinical performance of the MIRA method for detecting hvKP were evaluated. In total, 21 cases of hvKP were screened from clinical isolates. The MIRA detection method utilizes specific primers and probes to transmit significant fluorescence signals at 39°C, and the detection process takes 30 minutes. The specificity test results showed that only hvKP had a specific amplification curve, while the rest of non-highly virulent Klebsiella pneumoniae (non-hvKP) had no specific amplification curve. The sensitivity test results showed that the sensitivity of MIRA for detecting hvKP is 7 × 102 CFU/mL, which is consistent with the sensitivity of the real-time fluorescence qPCR method. A simultaneous detection of 184 clinical isolates was accomplished by using MIRA and qPCR methods. Twenty-one strains of hvKP have specific amplification curves, while the remaining 163 strains of non-hvKP have no specific amplification curves. The accuracy of both methods for detecting hvKP is 100%. The established multienzyme isothermal rapid amplification (MIRA) has the following characteristics: a short detection time, high sensitivity, and a strong specificity, and it can be used as a powerful tool for an early diagnosis and epidemiological monitoring of hvKp.

A hybrid approach for efficient feature selection in anomaly intrusion detection for IoT networks

The exponential growth of Internet of Things (IoT) devices underscores the need for robust security measures against cyber-attacks. Extensive research in the IoT security community has centered on effective traffic detection models, with a particular focus on anomaly intrusion detection systems (AIDS). This paper specifically addresses the preprocessing stage for IoT datasets and feature selection approaches to reduce the complexity of the data. The goal is to develop an efficient AIDS that strikes a balance between high accuracy and low detection time. To achieve this goal, we propose a hybrid feature selection approach that combines filter and wrapper methods. This approach is integrated into a two-level anomaly intrusion detection system. At level 1, our approach classifies network packets into normal or attack, with level 2 further classifying the attack to determine its specific category. One critical aspect we consider is the imbalance in these datasets, which is addressed using the Synthetic Minority Over-sampling Technique (SMOTE). To evaluate how the selected features affect the performance of the machine learning model across different algorithms, namely Decision Tree, Random Forest, Gaussian Naive Bayes, and k-Nearest Neighbor, we employ benchmark datasets: BoT-IoT, TON-IoT, and CIC-DDoS2019. Evaluation metrics encompass detection accuracy, precision, recall, and F1-score. Results indicate that the decision tree achieves high detection accuracy, ranging between 99.82 and 100%, with short detection times ranging between 0.02 and 0.15 s, outperforming existing AIDS architectures for IoT networks and establishing its superiority in achieving both accuracy and efficient detection times.

A Clinically Feasible Diagnostic Typing of Breast Cancer Built on a Homogeneous Electrochemical Biosensor for Simultaneous Multiplex Detection.

Simultaneous detection of multiple tumor markers is of great significance for an accurate diagnosis and early treatment of cancer. Electrochemical homogeneous biosensing strategies have been shown to have advantages, such as high sensitivity and no electrode modification, but they are still a challenge in the field of simultaneous detection of multiple tumor markers. The ER, PR, HER2, and Ki67 proteins are the standard biomarkers for the clinical molecular typing of breast cancer. Precise, sensitive, and simultaneous detection of these four biomarkers is of great importance in the molecular typing of breast cancer, which helps in the creation of personalized treatment plans. In the present study, we developed an electrochemical homogeneous electrochemical bioplatform based on metal ions/SiO2NPs/magnetic beads for detection of the four biomarkers and simultaneous diagnosis of the 10 types of breast cancer directly in human serum at one system by a single electrode. The electrochemical bioplatform has a short detection time of 140 min; however, the current clinical tissue testing time takes about 1 week. Also, the electrochemical bioplatform selectively detects HER2, ER, Ki67, and PR in a range of 0-1000 pg/mL with detection limits of 2, 1.8, 10.36, and 1.33 pg/mL, respectively.

The application of a novel biomimetic enzyme p-BEs cascade catalytic platform for the rapid detection of glucose

The blood glucose concentration in aquatic organisms, a crucial indicator reflecting their health status, holds significant importance for detecting glucose levels in serum in terms of processing and quality monitoring. In this study, a novel POD biomimetic enzyme (p-BEs) with horseradish peroxidase catalytic properties was designed, optimized, and its mechanism was discussed in detail. Based on this, a portable system has been developed capable of determining glucose levels in three ways: quantitatively analyzed through UV–Vis/MD, quantitatively analyzed on-site using a mobile phone RGB, and semi-quantitatively analyzed through a drip plate. Meanwhile, compared with other catalytic methods for detecting glucose, we achieved a lower limit of detection (0.03 μM) and shorter detection time (12 min), with high catalytic activity. This study provides new insights into the design of efficient and reliable cascade catalytic systems responsive to glucose, offering a low-cost, simplicity of operation method for glucose detection.

A Clinically Feasible Diagnostic Electrochemical Micronano Motors Biosensor Built on Miniature Swimmer for Multiplex Detection and Grading of Breast Cancer Biomarkers.

Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), and Ki67 are four crucial biomarkers used in the clinical diagnosis of breast cancer. Accurate detection of these biomarkers is essential for an effective diagnosis and treatment. MOF-based micronano motors (MOFtors) are promising for various applications, including environmental remediation, targeted nanosurgery, and biomarker detection. This paper presents a clinically feasible diagnostic electrochemical micronano motor biosensor, built on a miniature swimmer, for the multiplex detection and grading of breast cancer biomarkers. We designed a biosensor, named MOFtor-MSEM, incorporating aptamers and antibodies functionalized on SiO2@Co-Fe-MOF, which acts as a miniature swimmer in solution. The SiO2@Co-Fe-MOF serves as the body, while complementary double-chain-linked antibodies function as paddles. In a homogeneous solution, when a positive voltage is applied to the working electrode, the electrostatic interaction between the neutral SiO2@Co-Fe-MOF and the negatively charged complementary double-linked antibody causes the antibody to move toward the electrode and then regress due to water resistance. This back-and-forth motion propels the miniature swimmer, enabling it to move the target analyte through the solution. The sensor features an automatic "sample-amplifying signal-output" process, achieving simultaneous signal amplification and output of four electrochemical signals on a single nanomaterial, a significant challenge in electrochemical sensing. The biosensor boasts a short detection time of 40 min, compared to approximately 1 week for current clinical tissue testing. Additionally, the bioplatform selectively detects HER2, ER, Ki67, and PR in the range of 0-1500 pg/mL, with detection limits of 0.01420, 0.03201, 0.01430, and 0.01229 pg/mL, respectively.

Superimposed Positive Sequence Impedance for Detecting Unintentional Islanding in Microgrid

Incorporation of environmentally friendly energy sources (RESs) into the electricity grid has many benefits, including economic, technological, and environmental. However, excessive renewable energy sources (RES) in the power grid provide technical problems, including equipment protection, DG operation, and islanding detection. One of the most serious challenges is the islanding phenomenon. Islanding can cause several problems, such as frequency instability and voltage fluctuations resulting in damage to electrical equipment or threatening utility workers who may be working/accessing the equipment. This research proposes an efficient islanding detection algorithm to lessen the impact of such threats. This novel passive islanding detection scheme is based on superimposed positive sequence impedance (SPSI). For calculating the superimposed positive sequence impedance (SPSI), the voltage and current signals are obtained from targeted DG points. The scheme’s performance is tested on multiple bus systems across islanding and non-islanding conditions using a MATLAB/Simulink environment. It is shown that even in the presence of noise, the algorithm can determine an islanding decision with high accuracy and a short detection time of 84 ms. In comparison to other algorithms, it operates at zero power mismatch (ZPM) and does not affect power quality.

Rapid detection of carbapenemase-producing gram-negative bacteria directly from blood culture bottles for a reliable guided empiric therapy.

Bloodstream infections (BSIs) caused by multidrug-resistant bacteria are a critical life-threatening challenge which necessitates the urgency to trigger life-saving treatment in a timely manner. This study aimed to evaluate the time required for rapid detection of carbapenemase-producing Enterobacterales (CPE) directly from blood culture bottles to optimize empirical treatment of BSI, especially in pediatric and infant patients, using a cost-effective method. This study included 419 Gram-negative bacteria, of which Klebsiella pneumoniae and Escherichia coli were the most common CPE causing BSI in pediatric and neonatal patients. Phenotypic and genotypic resistance of the selected isolates (45 K. pneumoniae and 9 E. coli) were determined by VITEK-2 Compact system and PCR, respectively. BACT/ALERT bottles were spiked with isolates. Finally, colorimetric RESIST-BC assay and Vitek-2 compact system were evaluated for the rapid detection of carbapenem-resistant bacteria directly from positive blood culture bottles. All selected isolates were phenotypically resistant to carbapenems. PCR showed that blaNDM and blaOXA-48 were present in all isolates, blaVIM was present in 44.4%, while blaKPC and blaIMP were entirely absent. The RESIST-BC kit showed good agreement with PCR for blaNDM and blaOXA-48, demonstrating high sensitivity and specificity, but not with blaVIM. These findings point out that RESIST-BC assay demonstrated an exceptionally short detection time for CPE, completing all cases within the first hour after the blood culture bottles flagged positive. It is also superior in providing a cluefor clinicians on antibiotic combinations that can be administered, depending on the type of β-lactamases detected, promptly and efficiently, with low expenses.

Synthesis and application of the AIE-ESIPT fluorescent probe for Cystiene detection: Crystal structure analysis and DFT calculation

Accurate detection of Cysteine (Cys) in cells is critical for clinical diagnosis and pathogen detection. It was of practical significance to develop fluorescent probes with specific recognition and rapid detection of Cys. Therefore, based on the nucleophile reaction and intramolecular cyclization reaction between biothiols and acrylates (AAS), a fluorescence probe, BTY-TPE-AAS, was designed and synthesized by combining the advantages of the Aggregation-Induced Emission (AIE) and Excited-State Intramolecular Proton Transfer (ESIPT) mechanisms. BTY-TPE-AAS could specifically detect Cys with a short detection time and strong anti-interference, which had important application value in the monitoring of Cys in the biomedical field. It provided some reference values for the design of a specific fluorescent probe for Cys detection.

A fluorescent aptasensor for emetic Bacillus cereus detection based on DNA-functionalized magnetic separation coupled with rolling circle amplification

Foodborne pathogens have been a serious threat to human health and safety for a long time. However, the complex food substrate undoubtedly increases the difficulty of bacterial detection at low concentrations. How to effectively improve the sensitivity of bacterial detection is a major problem that needs to be solved. In this study, the aptamer of emetic Bacillus cereus (B. cereus) was used as the recognition molecule to construct a magnetic capture probe. Utilizing the strong affinity between target bacteria and the aptamer, a fluorescence sensor based on aptamer-rolling circle amplification (Apt-RCA) was established for the detection of emetic B. cereus in milk spiked samples. In this study, DNA-functionalized magnetic beads were first synthesized. The strong affinity between the aptamer and the target bacteria makes it to be used not only as an antibody substitute for capturing the target bacteria, but also to compete the complementary DNA (cDNA) strand of the aptamer on the DNA-functionalized magnetic bead as a primer for the subsequent RCA reaction. RCA reaction can produce RCA products rich in a large number of G-quadruplex sequences. The fluorescent dye thioflavin T (ThT) can bind to the G-quadruplex structure and produce an obvious fluorescence signal. The fluorescence signal amplification strategy based on the magnetic separation platform and RCA reaction successfully realized the sensitive detection of emetic B. cereus in actual sample. Under optimal conditions, the limits of detection (LODs) of pure bacterial solution and milk samples were 1.4 × 102 CFU/mL and 2.2 × 103 CFU/mL, respectively. This method has the advantages of short detection time, simple operation and good specificity, which provides a new way of thinking for the detection of foodborne pathogens.

Electrochemical and Plasmonic Detection of Myocardial Infarction Using Microfluidic Biochip Incorporated with Mesoporous Nanoscaffolds.

This paper reports a microfluidic device for the electrochemical and plasmonic detection of cardiac myoglobin (cMb) and cardiac troponin I (cTnI) with noticeable limits of detection (LoD) as low as a few picograms per milliliter (pg/mL) ranges, achieved in a short detection time. The device features two working electrodes, each with a mesoporous Ni3V2O8 nanoscaffold grafted with reduced graphene oxide (rGO) that improves the interaction of diffusing analyte molecules with the sensing surface by providing a high surface area and reaction kinetics. Electrochemical studies reveal sensitivities as high as 9.68 μA ng/mL and a LoD of 2.0 pg/mL for cTnI, and 8.98 μA ng/mL and 4.7 pg/mL for cMb. Additionally, the surface plasmon resonance (SPR) studies demonstrate a low-level LoD of 8.8 pg/mL for cMb and 7.3 pg/mL for cTnI. The dual-modality sensor enables dynamic tracking of kinetic antigen-antibody interactions during sensing, self-verification through providing signals of two modes, and reduced false readout. This study demonstrates the complementary nature of the electrochemical and SPR modes in biosensing, with the electrochemical mode being highly sensitive and the SPR mode providing superior tracking of molecular recognition behaviors. The presented sensor represents a significant innovation in cardiovascular disease management and can be applied to monitor other clinically important biomolecules.

Abstract PO5-16-03: RT LAMP assay for the subtyping of breast cancer

Abstract Introduction Our previous study showed that direct reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay can be employed as a substitute in order to detect tumor involvement of lymph nodes within breast cancer patients. In this research, we aimed to investigate the potential applicability of RT-LAMP for the classification of breast cancer subtype. Method Breast Cancer Cell line RNA extraction Total RNA from the cell lines was isolated from cultured cells using RNAiso Plus (TaKaRa, Shiga, Japan) according to the manufacturer’s instructions; MCF10A, MCF7, T47D, BT474, SKBR3, MB468, HCC1806, MB231 Primer design For the Primer design, ER, PR, HER2, Ki 67, CK7 and GATA were targeted. LAMP primers targeted at ER were created between exons 5 and 6, PR were created between exons 6 and 7, HER2 were created between exons 17 and 18, KI67 were created between exons 2 and 3, CK7 were created between exons 5 and 6, and GATA3 were created between exons 2 and 3 utilizing Primer Explorer V4 (http://primereplorer.jp/elamp4.00/index.html). RT-LAMP assays RT-LAMP assays were carried out within a 25 µL reaction which included 12.5 µL of 2 × reaction buffer, 2µL of each primer, 1 µL of enzyme mixture (16U Bst DNA polymerase and 120U M-MLV reverse transcriptase) 8 µL of DEPC-treated water, and 2 µL of the template RNA. DEPC-treated water was also employed for purposes of a negative control. The reaction mixture was conducted within qRT-PCR. Results ER, PR, HER2, Ki-67, CK7, GATA3 expression level were checked for each breast cancer cell line using RT-LAMP. The luminal cell line exhibited elevated levels of ER and PR expression, while the her2 cell line demonstrated a high level of expression for her2. In the RT LAMP assay, there is a direct correlation between shorter detection time and higher expression levels of the substance. Specifically, in the luminal type, ER/PR was detected within a timeframe of 10 to 12 seconds, while HER2 was detected within a timeframe of 15 to 16 seconds. The expression levels of ER, PR, and HER2 were compared between MCF7 (luminal A) and MDA-MB-231 (TNBC) cell lines. RT-LAMP was performed to examine the RNA expression levels, while RT-PCR was applied to confirm the cDNA expression levels. MCF7 and MDA-MB-231 were mixed at 1:9, 5:5 and 9:1 ratios, respectively, and the difference in ER/PR/HE2 expression level was confirmed (Table1, Figure1). The presence of ER was detected in the MCF7 cell line at 14.44 minutes, and PR was observed at 18.84 minutes. HER2 was detected at a similar time (approximately 15 minutes) in both the MCF7 and MB 231 cell lines. Conclusion This study demonstrated that ER, PR, and HER2 can be quantified using RT-LAMP. Ongoing experiments are being conducted to classify breast cancer using the RT-LAMP method, aiming to enhance sensitivity in the quantification of ER, PR, and HER2. Additionally, new primers are being developed specifically for HER2 detection. RT-LAMP offers the advantages of being a point-of-care test that can be conducted on-site and reducing the discrepancies between pathologists. Citation Format: In Hee Lee, Byeongju Kang, Jeeyeon Lee, Jin Hyang Jung, Ho Yong Park, Nora Jee-Young Park, Ji-Young Park, Eun Ae Kim, Jieun Kang, Yee Soo Chae, Soo Jung Lee. RT LAMP assay for the subtyping of breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-16-03.

DNA tetrahedron-based dual-signal fluorescence detection of apoE4 gene sites on a microplate reader.

As a neurodegenerative disorder, Alzheimer's disease (AD) is characterized by cognitive dysfunction and behavioral impairment. Among the various genetic risk factors for AD, apoE4 gene plays a pivotal role in the onset and progression of AD, and detection of apoE4 gene holds significance for prevention and early diagnosis of AD. Herein, dual-signal fluorescence detection of fragments associated with apoE ε4 allele near codon 112 (Tc1) and codon 158 (Tc2) was achieved using DNA tetrahedron nanostructure (DTN). The Förster resonance energy transfer (FRET) process in the DTN was initiated in which the nucleic acid intercalating dye thiazole orange (TO) served as the donor and the cyanine dyes of cyanine3 (Cy3) and cyanine5 (Cy5) at the two vertices of DTN served as the acceptors. In the presence of Tc1 and Tc2, the FRET process between TO and the cyanine dyes was hindered by the enzymatic cleavage reaction, which ensures the dual-signal fluorescence assay of apoE4 gene sites. The limit of detection for Tc1 and Tc2 was estimated to be 0.82nM and 0.77nM, respectively, and the whole assay was accomplished within 1h on a microplate reader. The proposed method thus possesses the advantages of easy operation, short detection time, and high-throughput capability.

N/S co-doped carbon dots-based solution-gated graphene transistors (SGGT) for ultra-sensitive and selective determination of Hg (II) ions in real water and serum samples

The conventional methods for detecting Hg2+ ions are generally impaired by low sensitivity, a high limit of detection (LOD), and the long detection time required. In this work, we develop a novel solution gated graphene transistor (SGGT) based on carbon dots doped with N and S elements (N/S CDs) as gate electrode probes. The prepared N/S CDs, which are 3–5 nm in diameter, are first modified at the gate of the SGGT through covalent bonding that specifically recognizes Hg2+ ions. The SGGT is then used as a Hg2+ sensor, exhibiting good selectivity, ultrahigh sensitivity, good reproducibility, and a short detection time. The SGGT sensor has an excellent linear detection range, from 0.1 fM to 1 nM. The LOD can reach 28 aM, which is far lower than that of conventional detection methods. Moreover, the SGGT sensor also has a rapid response time of ∼ 40 s. Finally, the ability to analyze real water samples and serum samples is demonstrated.