Dual Detection Research Articles

Design and fabrication of a dual laser Raman spectrometer with a single one-dimensional CCD detector.

The combination of two spectrometers in dual-laser Raman devices without the need for moving parts represents a significant advancement. This study focuses on design and fabrication of a dual spectrometer with no moving components, allowing data to be gathered using a single detector. This instrument consists of two Czerny-Turner optical arrangements which is symmetrically merged. Dual spectrometer single detector has two light inputs, each of them, concentrating the light separately on a one linear charge-coupled device detector through two independent optical paths. In this innovative spectrometer design, no optical moving parts are used, and therefore, the wavelength displacement error in repeating the spectroscopic experiment is zero. The independent nature of the optical paths enables the optimization of each spectrometer arrangement without affecting the other. The final spectrometer has a spectral resolution of 4.6 and 6.11cm- 1 for Full Width at Half Maximum across the wavelength ranges of 532 to 708nm and 784.65 to 1100nm, respectively. Switching between the two different acquisition setups can be done seamlessly and quickly, with the ability to record approximately 2000 spectra per second. Standard neon and mercury-argon lamps' atomic radiation spectra, along with Raman scattering data from a cyclohexane standard sample, were successfully recorded using laser wavelengths of 532nm and 784.65nm.

Rapid Dynamic Surface-Enhanced Raman Spectroscopy Detection of Amoxicillin-Mediated Morphological Changes in a Pathogen for Diagnosis of Clinical Urine Samples.

The swift and stable detection of pathogens in urine samples holds significant implications for the immediate clinical diagnosis and treatment of urinary tract infections (UTIs). In this study, we propose a detection strategy utilizing a hybrid substrate composed of graphene oxide (GO) and silver nanoparticles (Ag NPs) for the detection of pathogens subjected to amoxicillin-mediated (amo-mediated) treatment. This strategy employs dynamic surface-enhanced Raman spectroscopy (D-SERS) for stable and rapid detection, capturing signal variations induced by amo-mediated changes in pathogen morphology. During the 5 min D-SERS detection time window, stable SERS signals were detected for three types of pathogens and four types of pathogens were successfully distinguished using principal component analysis (PCA). In comparison to conventional nanosubstrates, the GO/Ag NP hybrid substrate exhibits outstanding stability and enhancement effects. This approach enables the dual detection of the pathogen cell structure and metabolites, facilitating specific identification of pathogens in the urinary tract, with a detection limit for Escherichia coli reaching 1 × 104 colony-forming units (CFU)/mL, meeting the clinical microbiology laboratory diagnostic standards for UTIs (105 CFU/mL). Testing of 188 clinically collected urine samples using this strategy yielded a sensitivity (SENS) of 86.4% and a specificity (SPC) of 89.7%. This introduces a novel method for diagnosing UTIs, offering broad applications in the field of clinical pathogen detection.

Dual Detection of Norfloxacin and Gatifloxacin by Excitation Tuning Strategy Based on Yellow Carbon Dots.

Fluoroquinolones (FQs) are widely used in hospitals, animal husbandry and aquaculture for the treatment of infectious diseases. However, overuse of FQs poses a potential threat to the environment and human. Detection of antibiotics is of great importance in various fields. In this paper, bright yellow fluorescence carbon dots (y-CDs) with quantum yield of 32% were synthesized via a simple and rapid microwave-assisted method using o-phenylenediamine and salicylic acid as raw materials. The fluorescence properties of y-CDs varied under different excitation wavelengths. It is discovered that the excitation wavelength is a critical factor to develop a dual functional fluorescence probe. Under selected excitation wavelength (355nm), y-CDs can realize dual detection of norfloxacin (NOR) and gatifloxacin (GAT) with good selectivity and high sensitivity in a "turn-on" mode. The detection limits of NOR and GAT are 0.0881 µM and 0.0125 µM, respectively. y-CDs prove practical application in the detection of NOR and GAT in milk and egg samples.

Enhanced dual lane detection in automotive radar systems using harmonic coordinated beamforming of time-modulated arrays

Enhanced dual lane detection in automotive radar systems using harmonic coordinated beamforming of time-modulated arrays

Pd-W18O49 Nanowire MEMS Gas Sensor for Ultraselective Dual Detection of Hydrogen and Ammonia.

Demand for real-time detection of hydrogen and ammonia, clean energy carriers, in a sensitive and selective manner, is growing rapidly for energy, industrial, and medical applications. Nevertheless, their selective detection still remains a challenge and requires the utilization of diverse sensors, hampering the miniaturization of sensor modules. Herein, a practical approach via material design and facile temperature modulation for dual selectivity is proposed. A Pd nanoparticles-decorated W18O49 nanowire gas sensor is prepared for dual detection of hydrogen and ammonia. The sensor exhibits distinct operating temperatures for ultraselective detection of hydrogen (125°C) and ammonia (225°C), with high responses of 35.3 and 133.8, respectively. This dual selectivity with high sensitivity is attributed to enhanced oxygen adsorption, the chemical affinity of sensing materials for target gases, and distinct reactivity profiles of gases. The proposed sensor is further integrated into a microelectromechanical system, enabling its small size, low power consumption, and rapid temperature modulation. Moreover, the practical feasibility of this sensor platform for smart energy monitoring systems is demonstrated by assessing its sensing properties in electrochemical ammonia oxidation reaction systems. This work can provide a practical approach for developing a single gas sensor with multiple functionalities for application in electronic nose systems.

Nanowire-like phosphorus modulated carbon-based iron nanozyme with oxidase-like activity for sensitive detection of choline and dye degradation

Choline is mainly supplemented through food intake, lack of choline would result in diseases like liver cirrhosis, hardening of the arteries, or neurodegenerative disorders. The accurate detection of choline is important for human health. Herein, a novel nanowire-like phosphorus/nitrogen co-doped carbon-based iron nanozyme (Fe-NPC) with outstanding oxidase-like activity was synthesized, and the influence of phosphorus doping on oxidase-like activity was explored. Proper phosphorus doping was found to enhance the oxidase-like activity of Fe-NPC by increasing surface defects, promoting iron loading, and modulating chemical environment of central site. The oxidase-like activity of Fe-NPC was successfully applied to colorimetric-fluorescent dual mode detection of choline, and good linear relationship in the ranges of 3–200 μM were achieved with LODs of 1.95 and 1.50 μM, respectively. The fluorescent detection was constructed based on the fluorescence quenching of silicon quantum dots (Si QDs) by quinone-imine. The quenching mechanism was attributed to FRET due to the large spectra overlap, reduced fluorescence lifetime and proper donor−acceptor distance. The successful application to the detection of choline in milk proved the practicability of the proposed sensing method. The oxidase-like properties of Fe-NPC was further used in the degradation of cationic dye methyl blue, high degradation efficiency of 74 % was achieved within 5 min under optimal conditions, proving the enormous potential of Fe-NPC for application in environment protection.

Ni-doped (MoO3/MoS2) heterostructure chemiresistive sensor for dual selective detection of NH3 and NOx at room temperature

The transition metal dichalcogenide heterostructures are emerging as promising candidates for room-temperature gas sensors. This work presents a Ni-doped (MoO3/MoS2) heterostructure, synthesized via hydrothermal methods with varying Ni concentrations, for the dual selective detection of NH3 and NOx gases. The electronic sensitization of Ni improves the sensitivity of heterostructure. The heterostructure was characterized by using X-ray diffractometer, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM), with Ni incorporation confirmed by X-ray photoelectron spectroscopy (XPS). The 10 % Ni-doped MoO3/MoS2 heterostructure showed high sensitivity, achieving responses of 15 % and 18.3 % towards 10 ppm NH3 and NOx, respectively, with detection limits of 0.13 ppm and 0.11 ppm. Furthermore, the sensor demonstrated outstanding cyclic stability, device-to-device reproducibility, and long-term stability, with a retained response of 98.1 % and 98.5 % towards NH3 and NOx, respectively. These findings highlight the potential of Ni-doped (MoO3/MoS2) heterostructures for dual gas sensing applications at room temperature.

Dual trace detection of hazardous substances by aptamer-functionalized gold nanofilms based on surface-enhanced Raman spectroscopy

Dual trace detection of hazardous substances by aptamer-functionalized gold nanofilms based on surface-enhanced Raman spectroscopy

Determination of vitamin D3 content in cod liver oil using column-switching technique.

To develop a two-dimensional liquid chromatography method to determine the content of vitamin D3 in cod liver oil preparations. The samples were prepared by saponification and extraction, and the content of vitamin D3 was determined by two-dimensional liquid chromatography with dual-pump-single-valve switching dual detectors. The chromatographic column, capture device, and detection wavelength were optimized; the linearity, system suitability, recovery rate, repeatability and sample stability of the method were investigated, and further validated in actual sample determination. A column switching two-dimensional chromatography method was developed. In the first dimensional chromatography, an Agilent PoroShell SB-C8 (50 mm×4.6 mm, 2.7 μm) column was used, and acetonitrile-water was used as mobile phase and gradiently eluted at a flow rate of 1.0 mL/min, the detection wavelength was 264 nm. An Agilent Zorbax SB-C18 (150 mm×3.0 mm,1.8 μm) column was used in the second dimensional chromatography, and acetonitrile was used as mobile phase at a flow rate of 0.42 mL/min, the detection wavelength was 264 nm. In determining content of Vitamin D3, there was a good linear relationship in the concentration range and the system suitability, recovery rate, repeatability and sample stability all met the verification requirements. The developed two-dimensional liquid chromatography method in the study is accurate, reproducible and simple, it can simultaneously separate pre-vitamin D3, trans-vitamin D3, vitamin D3, and tachysterol3, the baseline separation was achieved, indicating that it is worth promoting for application.

Early Diagnosis of Triple-Negative Breast Cancer Based on Dual microRNA Detection Using a Well-Defined DNA Crown-Carbon Dots Structure as an Electrochemiluminescence Sensing Platform.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer (BC). Thus, early detection and accurate diagnosis of this cancer are crucial for improving the survival rate of patients. Specific microRNAs (miRNAs) have been implicated in the occurrence, proliferation, and metastasis of TNBC. Addressing this need, our study developed a biosensor platform for early and accurate TNBC diagnosis by integrating electrochemiluminescence (ECL) technology with a DNA sensing strategy. Specifically, synthesized positively charged carbon dots (CDs) were used to neutralize the electrostatic repulsion between DNA strands and facilitate the assembly of DNA triangular prisms (DNA TP-CDs). Hairpins were then incorporated into the DNA TP-CDs to form the final DNA crown structure. The early TNBC biomarker, microRNA-93-3p (miR-93-3p), allowed for the binding between the DNA Crown and the DNA track on the electrode and initiated the ECL signal. Subsequently, microRNA-210 (miR-210) unlocked the DNA tripedal walker, and its movement on the DNA Crown eventually quenched the ECL signal, enabling accurate TNBC diagnosis and tumor stage assessment. Our proposed biosensor had satisfactory sensing efficiency due to the ordered DNA track and rapid-moving DNA walker. The data revealed a good linear relationship between the ECL signals and the logarithm of miRNA concentrations, with miR-93-3p having a detection limit of 31.04 aM and miR-210 having a detection limit of 7.69 aM. The biosensor also showed satisfactory performance in serum samples and cells. Taken together, this study hopes to provide ideas and applications for clinical diagnosis as well as the personalized treatment of TNBC.

A Novel Carbon Dot-Bromothymol Blue System for Ratiometric Colorimetric-Fluorometric Sensing of Glutathione in Urine: A Smartphone-Compatible Approach.

This study presents a novel dual-modal approach for glutathione (GSH) detection using blue and yellow dual-emission carbon dots (BY-CDs) and bromothymol blue (BTB) at pH 8.0. The method employs both colorimetric and fluorometric detection modes, offering a new perspective on GSH quantification. BTB's blue coloration induces selective fluorescence quenching of the CDs' 610nm emission peak, with minimal effect on the 445nm peak. Upon GSH addition, the quinonoid structure (blue color) of BTB transforms to its benzenoid form (yellow color). This transformation triggers fluorescence restoration at 610nm and significant quenching at 445nm, enabling ratiometric fluorescence analysis (F610/F445). Concurrently, colorimetric detection is also ratiometric, based on measuring the ratio between the emerging yellow color peak (435nm) and the decreasing blue color peak (618nm) (A435/A618). The state-of-the-art aspect of this detection method lies in the strategic choice of dual-emission CDs and a dye with distinct absorption spectra that closely match the emission spectra of the CDs. This unique combination allows for dual detection with opposite responses in the two detection modes, enhancing selectivity and reliability. The probe was thoroughly characterized, and its detection mechanism was elucidated using various spectroscopic techniques. The method shows excellent linearity, a broad detection range, and low detection limits for both fluorometry (0.02 - 10.0μM, 5.88nM) and colorimetry (1.0 - 35.0μM, 301.25nM). Additionally, a smartphone-based platform was developed for colorimetric GSH determination, enhancing the method's potential for on-site analysis. The assay's practicality was validated through successful application to human urine samples, yielding excellent recovery values (97.33% to 99.13%).

A Dual Detection Head YOLO Model With Its Application in Wheat Ear Recognition

The spike number(SN) per unit area is an important indicator for measuring wheat yield. The use of AI to detect and count wheat ears is increasingly valued by researchers. In order to improve the accuracy of wheat ear recognition, the model is deployed on limited mobile devices to achieve accurate estimation of wheat yield. This paper proposes a lightweight hybrid design network Wheat-YoloNet based on improved YOLOv8 for wheat ear recognition. On the basis of the YOLOv8 network structure, we only retain small and large object detection heads, reducing the number of network parameters while ensuring detection performance. We added CBAM attention mechanism module to Backbone to improve the feature extraction performance of the model and introduce Wise-IoU to balance the samples. Compared with the YOLOv8n baseline model, the improved model has reduced parameter count by 33.3%, outperforming other comparison object detection algorithms, and can be deployed and run on devices with limited computing power.

Rapid and Efficient Dual Detection Of Zn2+ Ions and Oxytetracycline Hydrochloride Using a Responsive Fluorescent "On-Off" Sensor Based on Simple Salen-Type Schiff Base Ligand.

This research has progressed to an effective detection chemosensor of zinc, aluminum ions and oxytetracycline hydrochloride antibiotic based on the fluorescence technique. A straightforward method utilizing microwave irradiation was employed to synthesize the salen-type Schiff base ligand N,N'-bis(salicylaldehyde)4,5-dichloro-1,2-phenylenediamine (H2I), providing a good 70 % yield. In ethanol, the H2I sensor demonstrated remarkable rapidity, selectivity, and sensitivity in detecting zinc ions. The fluorescence spectrum exhibited a 44-fold substantial enhancement at 522 nm and achieved a low limit of detection (LOD) of 1.47 μM. Furthermore, the H2I probe's emission intensity increased by 124 times when compared to the ligand's ability to detect Al3+ ions at 494 nm with a LOD value of 7.4 μM. Additional research was done using the H2I probe's effective Zn2+ detection capability. The ability to recognize zinc ions in different real water samples demonstrated a recovery rate of 98.67 % to 103.31 %. Interestingly, a naked-eye visible fluorescence color of H2I solution impregnated filter papers turned colorless into yell ow under UV irradiation by adding Zn2+ ions, renders it suitable for developing a practical zinc ion detection kit test. In particular, the I-Zn2+ complex effectively quenched the fluorescence toward oxytetracycline hydrochloride (OTC) with a LOD value of 1.49×10-2 μM in DMSO:H2O (6 : 4, v/v). This is a novel and effective procedure for sensing OTC antibiotic by the I-Zn2+ complex. These findings hold immense potential for the development of dual fluorescent probes, thereby enhancing sensitivity and specificity in identifying metal ions and antibiotics in a wide range of applications.

Amplified Sensitivity in SERS Detection of L1CAM With Silver Plasmonic Mesoporous Silica Capsules on an Imprinted Films

AbstractThis study presents a novel approach for dual detection, leveraging a combination of a Raman reporter‐bearing nanomaterial and molecular imprinting polymers (MIP). A core‐shell Au‐Ag nanoparticles (Au‐Ag NPs) encapsulated in mesoporous silica nanocapsules (Au‐Ag NCs) and a new MIP‐based material targeting L1CAM are used. The MIP prepared via surface imprinting on a carbon screen‐printed electrode (C‐SPE) used thionine (TH) as a monomer. The plasmonic Au‐AgNCs are further functionalized with the Raman reporter 4‐mercaptobenzoic acid (MBA) and anti‐L1CAM for selective detection by surface‐enhanced Raman scattering (SERS) spectroscopy. The biosensor's analytical performance is evaluated using both SERS and electrochemical impedance spectroscopy (EIS). EIS analysis reveals a linear response within the concentration range of 0.1 to 100 ng mL−1 in buffer and serum samples. SERS demonstrates a sensitivity ten times higher than EIS. Selectivity study demonstrates the biosensor's excellent specificity toward L1CAM, with minimal interference from other compounds such as creatinine, glucose, and carbohydrate antigen 19‐9 (CA 19‐9). The Raman signal from the reporter molecule correlates with increasing L1CAM concentrations, reinforcing the analytical findings obtained through electrochemical analysis. Thus, the combination of dual detection and recognition capabilities presents promising potential for detecting diverse biomarkers, especially in critical scenarios where reducing false‐positive or false‐negative errors is crucial.

Dual detection of Neoehrlichia mikurensis and Anaplasma phagocytophilum: How biplex PCR led in France to the diagnosis of neoehrlichiosis in post-tick bite fever

ObjectivesNeoehrlichia mikurensis (NM) is an emerging intracellular bacterium member of the Anaplasmatacecae family. So far, only four cases have been described in France, all of them retrospectively. MethodsThis study describes two new cases of NM discovered following implementation of a biplex PCR targeting both Anaplasma and NM. ResultsTwo immunocompetent patients developed a flu-like illness within 14 days after an identified tick bite. Both had negative Anaplasma PCR, but by using this biplex PCR NM, infection was diagnosed in both cases. One patient recovered spontaneously while the second was successfully treated by a seven-day course of doxycycline. ConclusionPresent in Eastern France, NM is underdiagnosed. Biplex PCR screening of NM with A.phagocytophilum could effectively address this issue.

Dual-modal detection of antimicrobial susceptibility in pathogenic bacteria based on the high-throughput microfluidic platform

For pathogenic bacterial infectious diseases such as sepsis, accurate and rapid antimicrobial susceptibility testing (AST) plays an important role in improving antimicrobial screening and clinical outcomes. Traditional culture-based AST assays have the limitations of time-consuming, labor-intensive, expensive, and consuming reagents. In this work, a simple, fast, high-throughput microfluidic platform integrated with isolation, identification, and detection functions was designed for antibiotic susceptibility analysis in pathogenic bacteria. For the above purpose, MnO2@ZIF-90 nanoprobes with dual functions of nanozyme and fluorescence were prepared for visual eye or RGB analysis through a smartphone APP. More importantly, the redox activity of bacterial membrane in active pathogenic bacteria could decompose the MnO2 of MnO2@ZIF-90 nanoprobes and reduce the enzyme-like activity, which weakens the colorimetric signal of Timebox. Meanwhile, the ATP released from active pathogenic bacteria further triggered the breakdown of the inner ZIF-90 layer, generating a fluorescence signal. Therefore, a dual detection combining colorimetric and fluorescence was used to perform more accurate and reliable antibiotic susceptibility analysis of pathogenic bacteria. With the proposed microfluidic platform, a low detection of 10 CFU mL−1 bacteria and fast AST results were achieved within 5 min. The clinical applicability of the platform was further demonstrated through the analysis of clinical samples. This work provides a low-cost, easy-to-operation, fast-response, and high-throughput platform for the AST assays in pathogenic bacterial infectious diseases such as sepsis.

7831 Unveiling Drug Resistance Mechanisms In Triple-Positive Breast Cancer: Insights From Long-Term Estrogen Deprivation Models And Innovative Mutation Detection Strategies

Abstract Disclosure: S. Bahnassy: None. H.S. Andrews: None. L. Jin: None. B.F. Kohrn: None. S. Tam: None. D. Mobin: None. Y.J. Dunn: None. M. Balachandran: None. M. Podar: None. W. He: None. M.D. McCoy: None. R.A. Beckman: Consulting Fee; Self; AstraZeneca, Boehringer Ingelheim. Other; Self; Chief Scientific Officer of OncoMind, LLC, which owns patents on dynamic precision medicine. R.B. Riggins: None. Compelling evidence from preclinical and clinical data suggests that triple-positive (TP; HER2+/HR+) breast cancer (BC) has lower response rates to HER2-targeted therapy and a higher risk of recurrence to endocrine therapy (ET) than HER2+/HR−. Molecular mechanisms underpinning drug resistance in TP-BC are poorly understood, thereby limiting our ability to improve patient outcomes and prevent metastatic progression. In our recent publication, we established and characterized long-term estrogen deprivation (LTED) ET-resistant (ETR) TP-BC models that mimic resistance to aromatase inhibitors without using genetic manipulation approaches. We reported intrinsic subtype shifts towards non-luminal phenotypes, metabolic reprogramming, and acquiring mutations in genes encoding for transcription factors and chromatin modifiers, as potential mechanisms of ETR in our LTED models. The emergence of drug-resistant mutator subclones under treatment-induced selective pressures, coupled with limitations in shallow-depth whole genome sequencing coverage, highlight an unmet need to develop a strategy for visually monitoring, capturing, and mapping resistant subclones through a mutational phenotypic screen, an approach offering valuable insights for optimizing treatment schedules. To address this, we developed and applied an innovative dual fluorescence mutation detection system to detect mutator cells expressing both mCherry and green fluorescence protein (GFP). First, we validated if our system is working properly. Compared to parental cells, transduced BT-474 and MDA-MB-361 LTEDs showed a drastic increase in GFP+ cells, suggesting the presence of resistant mutator cells. Consistent with the increase in GFP signal, TP-LTEDs showed increased mutation number and frequency in two Duplex Sequencing targeted capture panels (neutral loci and DNA polymerase-focused), used to perform ultra-deep, highly accurate sequencing. We then treated parental cells with single, dual, and triple combinations of anti-HER2, ET and CDK4/6 inhibitors to track the emergence of GFP+ mutator cells. Nine-day treatments with triple combinatorial therapies were best at inhibiting the growth of both BT-474 and MDA-MB-361 parental cell lines, compared to single- and double-agent targeted therapies. However, no GFP signal was detected within treated cells, suggesting that longer treatment durations are needed for drug-resistance mutator subclones to be discovered. Ongoing studies monitoring TP-drug resistance mutator subclones with long-term conventional targeted-therapies will improve our understanding of drug resistance mechanisms in this understudied subtype of BC. Importantly, these studies will enable dynamic precision medicine simulations to empower for a more tailored and effective therapeutic administration to prevent drug resistance and metastatic progression of TP-BC. Presentation: 6/3/2024

7831 Unveiling Drug Resistance Mechanisms in Triple-Positive Breast Cancer: Insights from Long-Term Estrogen Deprivation Models and Innovative Mutation Detection Strategies

Abstract Disclosure: S. Bahnassy: None. H.S. Andrews: None. L. Jin: None. B.F. Kohrn: None. S. Tam: None. D. Mobin: None. Y.J. Dunn: None. M. Balachandran: None. M. Podar: None. W. He: None. M.D. McCoy: None. R.A. Beckman: Consulting Fee; Self; AstraZeneca, Boehringer Ingelheim. Other; Self; Chief Scientific Officer of OncoMind, LLC, which owns patents on dynamic precision medicine. R.B. Riggins: None. Compelling evidence from preclinical and clinical data suggests that triple-positive (TP; HER2+/HR+) breast cancer (BC) has lower response rates to HER2-targeted therapy and a higher risk of recurrence to endocrine therapy (ET) than HER2+/HR−. Molecular mechanisms underpinning drug resistance in TP-BC are poorly understood, thereby limiting our ability to improve patient outcomes and prevent metastatic progression. In our recent publication, we established and characterized long-term estrogen deprivation (LTED) ET-resistant (ETR) TP-BC models that mimic resistance to aromatase inhibitors without using genetic manipulation approaches. We reported intrinsic subtype shifts towards non-luminal phenotypes, metabolic reprogramming, and acquiring mutations in genes encoding for transcription factors and chromatin modifiers, as potential mechanisms of ETR in our LTED models. The emergence of drug-resistant mutator subclones under treatment-induced selective pressures, coupled with limitations in shallow-depth whole genome sequencing coverage, highlight an unmet need to develop a strategy for visually monitoring, capturing, and mapping resistant subclones through a mutational phenotypic screen, an approach offering valuable insights for optimizing treatment schedules. To address this, we developed and applied an innovative dual fluorescence mutation detection system to detect mutator cells expressing both mCherry and green fluorescence protein (GFP). First, we validated if our system is working properly. Compared to parental cells, transduced BT-474 and MDA-MB-361 LTEDs showed a drastic increase in GFP+ cells, suggesting the presence of resistant mutator cells. Consistent with the increase in GFP signal, TP-LTEDs showed increased mutation number and frequency in two Duplex Sequencing targeted capture panels (neutral loci and DNA polymerase-focused), used to perform ultra-deep, highly accurate sequencing. We then treated parental cells with single, dual, and triple combinations of anti-HER2, ET and CDK4/6 inhibitors to track the emergence of GFP+ mutator cells. Nine-day treatments with triple combinatorial therapies were best at inhibiting the growth of both BT-474 and MDA-MB-361 parental cell lines, compared to single- and double-agent targeted therapies. However, no GFP signal was detected within treated cells, suggesting that longer treatment durations are needed for drug-resistance mutator subclones to be discovered. Ongoing studies monitoring TP-drug resistance mutator subclones with long-term conventional targeted-therapies will improve our understanding of drug resistance mechanisms in this understudied subtype of BC. Importantly, these studies will enable dynamic precision medicine simulations to empower for a more tailored and effective therapeutic administration to prevent drug resistance and metastatic progression of TP-BC. Presentation: 6/3/2024

Fe7S8 nanosheets- catalyzed colorimetric and fluorescence dual ratio sensing for high selectivity detection of ascorbic acid

By using Fe7S8 nanosheets (NSs) as catalyst, O-phenylenediamine (OPD) as chromogenic substrate, H2O2 as oxidant, and ascorbic acid (AA) as regulator, a dual ratio colorimetric and fluorescence sensing system for determining AA was constructed. The inherent peroxidase like activity of Fe7S8 NSs enables it to catalyze the oxidation of OPD in the existence of H2O2, resulting in the formation of yellow-colored 2, 3-diaminophenazine (DAP) with a characteristic absorption peak at 450 nm and a fluorescence emission peak at 560 nm. However, the presence of AA could suppress the oxidation of OPD and induce the generation of quinoxaline derivative (QXD) 3-(dihydroxyethyl) furo [3,4-b] quinoxaline-1-one with absorption and fluorescence emission peaks located at 345 and 435 nm, respectively. Thus, employing the absorption of QXD at 345 nm and emission at 435 nm as the reporting signals, and the absorption of DAP at 450 nm and emission at 560 nm as the reference signals, a ratio colorimetric (A345/A450) and ratio fluorescence (F435/F560) dual signal detection method for AA was developed. Under the optimized conditions, the value of A345/A450 was found to be linear with AA concentration in the ranges of 1.0–40 μM and 40–100 μM, and the value of F435/F560 was strongly correlated with AA concentration in the ranges of 1.0–30 μM and 30–100 μM. When applied for the assay of AA in human serum samples, an acceptable recovery ranging from 93.1 to 106.6 % was obtained, confirming the potential of the sensing system in practical applications.

Design of a portable bioassay system based on highly efficent nanozyme and Au-DNA nanocluster: Toward current/colorimetric dual-signal detection of sugarcane smut

Sugarcane smut is a major agricultural pest affecting sugarcane yield and quality, posing a significant threat to the sustainable and healthy development of the global sugar industry. The best strategy for controlling Sugarcane smut is early and precise diagnosis. An intelligent mobile bio-platform is constructed based on Au-Co/Zn ZIF nanozymes and Au-DNA nanoclusters for current/colorimetric dual signal detection of the sugarcane smut pathogen. Efficient and specific cycling of the specific gene fragment (bE4′) for Sugarcane smut is achieved by strand displacement reaction. The output strand then forms Au-DNA nanoclusters with AuNPs-DNA, and the bioconjugate is captured by H2 probe, which results in the formation of more double-stranded structures, causing methylene blue (MB) to adsorb on electrode. The anodic nanozyme efficiently catalyzes the oxidation of glucose, generating a large number of electrons, and MB in the system is therefore reduced to MBH, causing a color change. This results in distinct current/colorimetric dual output signals, significantly enhancing the accuracy. A capacitor is further coupled with the system to improve the sensitivity. The detection signals are read in real-time by a smartphone. The developed method for sugarcane smut genes shows good linearity within a concentration range of 0.0001–10000 pM, with a detection limit as low as 23.59 aM (S/N = 3). This work integrates advanced technologies from various fields to create a portable sensing device with extremely high sensitivity and precision for detecting sugarcane smut. It provides a reliable new option for early and precise diagnosis of the disease and offers valuable theoretical and technical insights for early prevention, intelligent detection, and real-time monitoring of other plant diseases.