Simultaneous Detection Research Articles

Advances in Nanomaterial-Based Sensors for Early Disease Detection

Nanomaterial-based sensors are emerging as highly promising tools for the early detection of diseases, offering superior sensitivity, specificity, and miniaturization compared to traditional diagnostic methods. By leveraging the unique properties of nanomaterials such as gold nanoparticles, carbon nanotubes, graphene, and quantum dots, these sensors can detect disease biomarkers at much lower concentrations, enabling earlier diagnosis and intervention. This paper reviews the latest advancements in nanomaterial-based sensors, focusing on their applications in cancer, infectious diseases, and neurological disorders. Key developments include gold nanoparticle-based colorimetric sensors for cancer biomarker detection, graphene-based electrochemical sensors for prostate cancer and other malignancies, and quantum dot-based fluorescence sensors for both cancer and pathogen detection. Despite their promise, challenges remain, including issues with sensitivity, selectivity, reproducibility, biocompatibility, and scalability. Future directions for nanomaterial-based sensors involve improving their performance, developing multiplexed platforms for simultaneous detection of multiple biomarkers, and integrating these sensors into wearable or point-of-care devices. Overcoming these challenges and achieving regulatory approval will be crucial for the widespread clinical adoption of these advanced sensors, ultimately transforming healthcare by enabling more effective, rapid, and accessible early disease detection.

Multi-Electrode Extended Gate Field Effect Transistors Based on Laser-Induced Graphene for the Detection of Vitamin C and SARS-CoV-2.

Despite the clinical data showing the importance of ascorbic acid (AA or vitamin C) in managing viral respiratory infections, biosensors for their simultaneous detection are lacking. To address this need, we developed a portable and wireless device for simultaneous detection of AA and SARS-CoV-2 virus by integrating commercial transistors with printed laser-induced graphene (LIG) as the extended gate. We studied the effect of laser printing pass number and showed that with two laser printing passes (2-pass LIG), the sensor sensitivity and limit of detection (LOD) for AA improved by a factor of 1.6 and 12.8, respectively. Using complementary characterization methods, we attribute the improved response to a balanced interplay of crystallinity, defect density, surface area, surface roughness, pore density and diameter, and mechanical integrity/stability. These factors enhance analyte transport, reduce noise/variability, and ensure consistent sensor performance, making 2-pass LIG the most effective material in this work. Our sensors exhibit promising performance for detecting AA with a selective response in the presence of common salivary interfering molecules, with sensitivity and LOD of 73.67 mV/dec and 54.04 nM in 1× phosphate buffered saline and 81.05 mV/dec and 78.34 nM in artificial saliva, respectively. We also showed that functionalization of the 2-pass LIG gate with S-protein antibody enables the detection of SARS-CoV-2 protein antigens with an ultralow LOD of 52 zg/mL─an improvement of more than 10-fold compared to 1-pass LIG─and 4 particles/mL for virion mimics with a selective response against influenza virus and multiple human coronavirus strains. With low signal drift/hysteresis and wireless capabilities, the developed device holds great potential for improving at-home monitoring and clinical decision-making.

In Situ Deprotection-Free Synthesis of Silver/Graphdiyne with a High Raman Sensing Effect for Detection of Polychlorophenols and Microplastics.

Since the first synthesis of graphdiyne (GDY), it has been widely receiving a lot of attention and has great application prospects in many fields, such as energy storage, catalysis, and sensing. However, the complex deprotection treatment and long reaction time limit its mass production and applications. Here, we present a strategy for the silver-catalyzed deprotection-free rapid synthesis of GDY. Crystalline GDY was synthesized in 8 h at room temperature and atmospheric pressure, and after the reaction, Ag nanoparticles with an ultrathin diameter of 2-3 nm were formed in situ inside and on the surface of GDY. This Ag/GDY composite exhibits a high specific surface area of 672.3 m2 g-1 and strong surface plasmon resonance behavior, showing a strong surface-enhanced Raman scattering effect. The enhancement factor and the lowest detection limit for rhodamine 6G are 3.54 × 108 and 1 × 10-14 M, respectively. The Ag/GDY achieves the simultaneous enrichment and detection of polychlorophenols and ultrafine nanoplastics.

Wearable Multifunctional Hydrogel for Oral Microenvironment Visualized Sensing Coupled with Sonodynamic Bacterial Elimination and Tooth Whitening.

Bacterial-driven dental caries and tooth discoloration are growing concerns as the most common oral health problems. Current diagnostic methods and treatment strategies hardly allow simultaneous early detection and non-invasive treatment of these oral diseases. Herein, a wearable multifunctional double network hydrogel combined with polyaniline and barium titanate (PANI@BTO) nanoparticles is developed for oral microenvironment visualized sensing and sonodynamic therapy. Due to the colorimetric properties of polyaniline, the hydrogel displays a highly sensitive and selective response for visualized sensing of oral acidic microenvironment. Meanwhile, the barium titanate in the hydrogel efficiently generates reactive oxygen species (ROS) under ultrasound irradiation, realizing non-invasive treatment in the oral cavity. Through bacterial elimination experiments and tooth whitening studies, the hydrogel can achieve the dual effect of effectively inhibiting the growth of cariogenic bacteria and degrading tooth surface pigments. Owing to the visualized sensing of the oral acidic microenvironment and efficient sonodynamic therapy function, the proposed hydrogel system offers a solution for the prevention of caries and tooth whitening, which is promising in developing the biomedical system targeting the simultaneous sensing and therapy for oral diseases.

A Highly Sensitive Dual-Slotted Channel-Based Sensor Coated with Gold and Titanium Dioxide for Simultaneous Detection of Two Distinct Analytes

A Highly Sensitive Dual-Slotted Channel-Based Sensor Coated with Gold and Titanium Dioxide for Simultaneous Detection of Two Distinct Analytes

Development of a Multiplex PCR Assay to Detect Neofusicoccum parvum and Botryosphaeria dothidea in Walnut.

In walnut orchards, frequent symptoms of cankers and dieback (fruit blight, twig and branch cankers up to tree death) are caused by different agents, in particular by Botryosphaeriaceae, primarily Neofusicoccum parvum and Botryosphaeria dothidea. This study aimed at developing a sensitive, rapid, specific and internally controlled multiplex PCR assay for the detection of these species. The ability of the multiplex PCR, with an internal inhibition control (i.e. E. coli DNA), to specifically and successfully detect members of the two targeted species was validated using 11 different isolates for each fungal target (inclusivity) and 20 tree-associated fungal species different from B. dothidea or N. parvum (exclusivity). Applicability to plant materials was further investigated and showed an absence of amplification for asymptomatic husk or twig samples while the amplification profiles of symptomatic tissues ranged from no amplification to amplification of both species, in correlation with the observed fungal contamination level. In conclusion, we developed a rapid diagnostic tool for simultaneous detection of two major fungal pathogens of walnut. Although this protocol was tailored for walnut husks and twigs, applicability to any plant sample contaminated by these pathogens can be considered.

Simultaneously Detecting the Power and Temperature of a Microwave Sensor via the Quantum Technique

This study introduces a novel method for the simultaneous detection of microwave sensor power and temperature, leveraging nitrogen-vacancy (NV) centers as a robust quantum system. Through precise measurement of the optical detection magnetic resonance contrast in NV centers, the microwave power is accurately determined. Furthermore, the temperature of the sensor is obtained by monitoring the variations in zero-field splitting and thorough spectral analysis. This method enables the efficient real-time acquisition of synchronized data on both microwave power and temperature from the sensor, facilitating concurrent monitoring without the necessity of additional sensing devices. Finally, we verified that the magnetic sensitivity of the system is approximately 1.2 nT/Hz1/2, and the temperature sensitivity is around 0.38 mK/Hz1/2. The minimum resolution of microwave power is about 20 nW. The experimental results demonstrate that this quantum measurement technique provides stable and accurate data across a wide range of microwave power and temperature conditions. These findings indicate substantial potential for this technique in advanced applications such as aerospace, medical diagnostics, and high-frequency communications. Future studies will aim to extend the industrial applicability of this method by refining quantum control techniques within NV center systems.

A novel electrochemical sensor based on ꞵ-cyclodextrin/bismuth oxybromide/multi-walled carbon nanotubes modified electrode with in situ addition of tetrabutylammonium bromide for the simultaneous detection and degradation of tebuconazole.

A novel electrochemical sensor-based glassy carbon electrode (GCE) was fabricated and appliedtosimultaneous detection and degradation of tebuconazole (TBZ) for the first time.TheGCE was consecutively modified by multi-walled carbon nanotubes (MWCNTs), bismuth oxybromide (BiOBr), ꞵ-cyclodextrin (ꞵ-CD), and in situ addition of tetrabutylammonium bromide (TBABr). The detection was based on the decreasing of Bi signal at its anodic potential (Epa) of 0.05V. Under the optimum conditions, the modified electrode exhibited a linear response to TBZ in the concentration range 1-100μg L-1 with a detection limit of 0.9μg L-1. TBZ was firstly adsorbed on the surface of the modified electrode through host-guest molecule interactions of the ꞵ-CD. The adsorption was further enhanced by the large surface area of BiOBr and MWCNTs. The adsorbed TBZ on the electrode surface hindered the electron transfer of Bi, thus decreasing the oxidation of Bi. In addition, the in situ addition of tetrabutylammonium bromide (TBABr) enriched TBZ via electrostatic interactions, increasing its detection sensitivity. The fabricated electrochemical sensor was applied to determine TBZ in water and soil samples from rice fields with recoveries of 80.5-100.5% and 87.6-112%, respectively. Furthermore, the degradation of TBZ on the modified electrode was studied under a solar light simulator. The degradation percentage (100%) of TBZ (50µg L-1) was achieved in5min owing to the excellent photocatalytic properties of BiOBr.

Dual Recognition Strategy‐Based Transistor Sensor Array for Ultrasensitive and Multi‐Target Detection of Antibiotics

AbstractMulti‐target detection is a notable development direction in the field of analytical methods, boasting significant potential for breakthroughs in complex sample detection. Herein, an extended gate field‐effect transistor (EGFET) sensor array for ultrasensitive and multi‐target detection of antibiotics is developed. To enhance the recognition ability for diverse antibiotics, a dual‐recognition strategy based on tailor‐made molecularly imprinted polymer (MIP) and aptamer is adopted to fabricate the extended gate electrode (sensing electrode). The dual‐recognition strategy‐based EGFET exhibits superior sensitivity, selectivity, and stability compared to single recognition probes due to the synergistic effect of the affinities of MIP and specific aptamer. The developed sensor array can detect three types of antibiotics, including ampicillin, amoxicillin, and kanamycin, at the same time with record‐low detection limit (fM level) and a detection range spanning six orders of magnitude. The practical detection of antibiotics in various samples (tap water, river water, milk, honey, and artificial urine) further validates the feasibility of the sensor array in practical applications. The key advantages of flexibility, high sensitivity and selectivity, and multifunctionality demonstrate the high potential of EGFET sensor array for simultaneous detection of multiple target molecules.

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae (and Its Resistance to Ciprofloxacin): Validation of a Molecular Biology Tool for Rapid Diagnosis and Treatment

Background and Objectives: Neisseria gonorrhoeae and Chlamydia trachomatis can cause similar clinical syndromes and may coexist in infections. In emergency medicine, empirical treatment targeting both pathogens is often employed, potentially contributing to antibiotic resistance. Gonococcal resistance has emerged against first-line antimicrobials, necessitating prior testing for fluoroquinolone susceptibility. Certest Biotec developed two molecular diagnostic products for simultaneous detection: VIASURE C. trachomatis & N. gonorrhoeae Real-Time PCR Detection Kit and VIASURE Neisseria gonorrhoeae Ciprofloxacin-Resistant Real-Time PCR Detection Kit. To evaluate these products, clinical performance assessments were conducted at the Clinical Microbiology Laboratory of Miguel Servet University Hospital in Zaragoza, Spain. Results and Conclusions: Both VIASURE assays under study demonstrated high clinical sensitivity and specificity compared to reference molecular assays and Sanger sequencing. These kits offer an accurate diagnosis, facilitating appropriate treatment choices while addressing concerns about emerging antibiotic resistance. Methods: A total of 540 clinical samples from 540 patients already characterized as positive or negative for CT and NG by a molecular assay and by antibiotic susceptibility testing for ciprofloxacin using a concentration gradient diffusion method were used for the clinical evaluation. In cases where sensitivity results were unavailable, conventional PCR and Sanger sequencing were employed.

Individual Tree Crown Detection and Classification of Live and Dead Trees Using a Mask Region-Based Convolutional Neural Network (Mask R-CNN)

Mapping the distribution of living and dead trees in forests, particularly in ecologically fragile areas where forests serve as crucial ecological environments, is essential for assessing forest health, carbon storage capacity, and biodiversity. Convolutional neural networks, including Mask R-CNN, can assist in rapid and accurate forest monitoring. In this study, Mask R-CNN was employed to detect the crowns of Casuarina equisetifolia and to distinguish between live and dead trees in the Pingtan Comprehensive Pilot Zone, Fujian, China. High-resolution images of five plots were obtained using a multispectral Unmanned Aerial Vehicle. Six band combinations and derivatives, RGB, RGB-digital surface model (DSM), Multispectral, Multispectral-DSM, Vegetation Index, and Vegetation-Index-DSM, were used for tree crown detection and classification of live and dead trees. Five-fold cross-validation was employed to divide the manually annotated dataset of 21,800 live trees and 7157 dead trees into training and validation sets, which were used for training and validating the Mask R-CNN models. The results demonstrate that the RGB band combination achieved the most effective detection performance for live trees (average F1 score = 74.75%, IoU = 70.85%). The RGB–DSM combination exhibited the highest accuracy for dead trees (average F1 score = 71.16%, IoU = 68.28%). The detection performance for dead trees was lower than for live trees, which may be due to the similar spectral features across the images and the similarity of dead trees to the background, resulting in false identification. For the simultaneous detection of living and dead trees, the RGB combination produced the most promising results (average F1 score = 74.18%, IoU = 69.8%). It demonstrates that the Mask R-CNN model can achieve promising results for the detection of live and dead trees. Our study could provide forest managers with detailed information on the forest condition, which has the potential to improve forest management.

Measurement of Four Uterine NK Cell Subtypes Using Multiplexed Fluorescent Immunohistochemical Staining in Women with Repeated Implantation Failure.

Immunohistochemistry (IHC) plays a crucial role in biological research and clinical diagnosis, serving as the most commonly used method for identifying and visualizing tissue antigens. However, traditional IHC staining methods have limitations in distinguishing various subtypes of immune cells. This challenge has driven scientists to explore new technologies and methodologies for precise identification and differentiation of immune cell subtypes. In recent years, multiplex IHC has emerged as a solution, enabling the simultaneous detection of multiple antigens and their visualization within the same tissue sample. Uterine natural killer (uNK) cells play a pivotal role in early pregnancy processes, including decidualization, remodeling of uterine spiral arteries, and embryo implantation. Different subtypes of uNK cells exhibit different functions, allowing them to coordinate various biological events for successful embryo development and pregnancy. Therefore, in-depth research on uNK cell subtypes is essential for elucidating immune regulation mechanisms during pregnancy. Such studies provide valuable insights and novel approaches for addressing related conditions such as infertility and recurrent reproductive failure. This paper introduces a detailed multiplex IHC staining protocol for studying the density of four subtypes of uNK cells in endometrial specimens during the window of implantation (WOI). The protocol includes sample preparation, optimization of subtype markers, microscopic imaging, and data analyses. This multiplex IHC staining protocol offers high specificity and sensitivity, enabling simultaneous detection of different uNK cell subtypes, thus providing researchers with a powerful tool to explore the intricacies and mechanisms of immune regulation during pregnancy.

Pump-free SERS microfluidic chip based on an identification-competition strategy for ultrasensitive and efficient simultaneous detection of liver cancer-related microRNAs

In this study, we present a pump-free SERS microfluidic chip capable of detecting liver cancer-related miR-21 and miR-155 concurrently with ultra-sensitivity and high efficiency. We employed a Fe3O4@cDNA-AuNPs@Raman reporter@H composite structure and a recognition competition strategy. When the target miRNAs (miR-21 and miR-155) are present in the test liquid, they specifically compete with the nucleic acid complementary strand(H) of Fe3O4@cDNA-AuNPs@Raman reporter@H, causing AuNPs to competitively detach from the surface of Fe3O4, resulting in a decrease in the SERS signal. Consequently, this pump-free SERS microfluidic chip enables the detection of the target miRNAs more rapidly and accurately in complex environments. This method offers an approach for the simultaneous and efficient detection of miRNAs and holds promising applications in the early diagnosis of liver cancer.

Highly sensitive multiplexed colorimetric lateral flow immunoassay by plasmon-controlled metal-silica isoform nanocomposites: PINs.

Lateral flow assay (LFA) systems use metal nanoparticles for rapid and convenient target detection and are extensively studied for the diagnostics of various diseases. Gold nanoparticles (AuNPs) are often used as probes in LFAs, displaying a single red color. However, there is a high demand for colorimetric LFAs to detect multiple biomarkers, requiring the use of multicolored NPs. Here, we present a highly sensitive multiplexed colorimetric lateral flow immunoassay by multicolored Plasmon-controlled metal-silica Isoform Nanocomposites (PINs). We utilized the localized surface plasmon resonance effect to create multi-colored PINs by precisely adjusting the distance between the NPs on the surface of PINs through the controlled addition of reduced gold and silver precursors. Through simulations, we also confirmed that the distance between nanoparticles on the surface of PINs significantly affects the color and colorimetric signal intensity of the PINs. We achieved multicolored PINs that exhibit stronger colorimetric signals, offering a new solution for LFA detection with high sensitivity and a 33 times reduced limit of detection (LOD) while maintaining consistent size deviations within 5%. We expect that our PINs-based colorimetric LFA will facilitate the sensitive and simultaneous detection of multiple biomarkers in point-of-care testing.

Single-walled carbon nanotubes hybrid carbon materials sensor for simultaneous detection of chloramphenicol and furazolidone in food samples

Single-walled carbon nanotubes hybrid carbon materials sensor for simultaneous detection of chloramphenicol and furazolidone in food samples

An electrochemical sensor for simultaneous voltammetric detection of ascorbic acid and dopamine enabled by higher electrocatalytic activity of co-modified MCM-41 mesoporous molecular sieve

It is of great value to develop effective methods for accurately and simultaneously detecting ascorbic acid (AA) and dopamine (DA) in the field of biochemistry. This work reports a nonenzymatic electrochemical sensor for the simultaneous detection of AA and DA by employing a Co-modified MCM-41 (CoMCM-41) mesoporous molecular sieve as an efficient electrocatalytic material, which was synthesized by a two-step hydrothermal method. Subsequently, the high structural organization of the CoMCM-41 mesoporous structure was characterized, and the electrocatalytic performance of CoMCM-41 toward AA and DA oxidation was then evidenced by the catalytic effect of different electrodes modified with or without CoMCM-41. By virtue of the superior electrocatalytic activity of the CoMCM-41, a much wider peak potential difference (ΔEpa) of 310 mV was obtained for the oxidation of AA and DA in their mixture solution, and the parameters that influenced the electrochemical signals of the modified electrode were also optimized. Under optimal conditions, a good linear response to AA and DA was observed on the CoMCM-41 modified electrode. For individual detection of AA and DA, the linear ranges were 7 ~ 105 μM and 5 ~ 110 μM respectively, while the linear response range was 20 ~ 100 μM for simultaneous detection of AA and DA. Satisfactory recovery results were obtained when the fabricated sensor was applied to determine AA in orange juice and DA in madopar pill samples.

An easy and sensitive assay for acetohydroxyacid synthases based on the simultaneous detection of substrates and products in a single step.

Acetohydroxyacid synthase (AHAS, EC 2.2.1.6) catalyzes the first step in the synthesis of the branched-chain amino acids valine, leucine, and isoleucine, pathways being present in plants and microorganisms, but not in animals. Thus, AHAS is an important target for numerous herbicides and, more recently, for the development of antimicrobial agents. The need to develop new and optimized herbicides and pharmaceuticals requires a detailed understanding of the biochemistry of AHAS. AHAS transfers an activated two-carbon moiety derived from pyruvate to either pyruvate or 2-oxobutyrate as acceptor substrates, forming 2-acetolactate or 2-acetohydroxy-2-butyrate, respectively. Various methods have been described in the literature to biochemically characterize AHAS with respect to substrate preferences, substrate specificity, or kinetic parameters. However, the simultaneous detection and quantification of substrates and unstable products of the AHAS-catalyzed reaction have always been a challenge. Using AHAS isoform II from Escherichia coli, we have developed a sensitive assay for AHAS-catalyzed reactions that uses derivatization with ethyl chloroformate to stabilize and volatilize all reactants in the aqueous solution and detect them by gas chromatography coupled to flame ionization detection or mass spectrometry. This assay allows us to characterize the product formation in reactions in single and dual substrate reactions and the substrate specificity of AHAS, and to reinterpret previous biochemical observations. This assay is not limited to the AHAS-catalyzed reactions, but should be applicable to studies of many metabolic pathways.

Light-Activated Gene Expression System Using a Caging-Group-Free Photoactivatable Dye.

Optical regulation of transcription using chemical compounds is an effective strategy to manipulate gene expression spatiotemporally. Conventional caging approaches with photoremovable protecting groups may require intense UV-light exposure and release potentially toxic byproducts. To address these problems, here we developed a light-mediated transcriptional regulation system by combining a caging-group-free photoactivatable dye PaX560 and a multidrug-binding transcriptional regulator QacR. The cationic dye generated from PaX560 through traceless photoconversion bound QacR and reduced its repressor function, resulting in transcriptional activation. Importantly, this system allowed transcriptional activation with a large dynamic range under mild visible light exposure and simultaneous detection of the state of the photoactivated effector. This module was integrated into the T7 RNA polymerase expression system to demonstrate light-activated transcription in vitro and in living cells.

CuO@3D graphene modified glassy carbon electrode towards the detection of Orange II and Rhodamine B

Synthetic dyes are illegally used in foodstuffs and cause serious health issues in humans due to their carcinogenic nature. To avoid serious health issues, it is compulsory to detect and remove even the minute quantities of these harmful dyes in foodstuffs. Electrochemical sensors are accredited as an efficient and promising platform for the robust and sensitive determination of food toxins in various foodstuffs. Therefore, an efficient, facile, and competent sensor is devised for the simultaneous detection of Orange II (OR II) and Rhodamine B (RhB) supported by rGO and CuO nanoparticles. The synergism between rGO’s immense surface area and the adsorption properties of CuO enhances selectivity and response time for the detection of OR II and RhB. This work elaborated the synthesis, characterization, and electrochemical behavior of CuO@3DGr electrode towards simultaneous sensing of OR II and RhB. Physicochemical techniques were utilized to validate the fabrication of targeted material. On the other hand, the electrochemical features of the developed sensor were characterized by cyclic voltammetry (CV) and electron impedance spectroscopy (EIS). Differential pulse voltammetry technique was employed to detect simultaneously Orange II and Rhodamine B on the surface of bare (GCE), GO/GCE, CuO/GCE, and CuO@3DGr/GCE. Multi-analyte detection is possible with DPV, a sensitive electrochemical method. Based on each toxin’s specific electrochemical signature, the sensor may generate separate peaks by delivering a sequence of potential pulses and detecting the ensuing current. The parameters which influence the performance of the modified sensor were carefully evaluated. Under ambient conditions, the developed sensor exhibited excellent electrocatalytic activity in oxidation at 0.67 V of OR II and 0.96 V RhB with a low limit of detection 08 nM for OR II and 4.5 nM for RhB in Britton- Robinson buffer (BRB pH:7). The described methodology allowed a robust and fast analysis of food toxins in different foodstuff establishing this sensor as a novel tool for detecting food toxins. Tap water was used to analyze the practical applicability of developed electrode material and suitable results were achieved. These results showed that the as-synthesized novel electrochemical sensor has the potential for ultrasensitive determination and detection of toxins in different foodstuffs.

42 Clinical features and severity of COVID-19 with respiratory virus coinfections versus SARS-CoV-2 monoinfection in hospitalized children: A Canadian national surveillance study

Abstract Background The co-circulation of SARS-CoV-2 alongside other respiratory viruses has led to the risk of coinfections, potentially intensifying the severity of cases, especially in children. Objectives This study examined the epidemiology, clinical characteristics, and outcomes of SARS-CoV-2 respiratory virus coinfections in comparison to SARS-CoV-2 monoinfections in hospitalized children. Design/Methods A nationwide surveillance study was conducted to assess paediatric COVID-19-related hospitalizations across Canada from April 2020 to May 2022. Data were captured through two datasets covering ~90% of all Canadian tertiary-care paediatric beds: The Canadian Paediatric Surveillance Program and the Canadian Immunization Monitoring Program, ACTive. Coinfections were defined as the simultaneous detection of SARS-CoV-2 and ≥1 other respiratory virus. Severe infection was defined as intensive care, ventilatory, or hemodynamic support needs, organ systems complications, or death. Variables and outcomes were summarized and compared, and risk ratios were computed using Poisson regression, adjusting for age, gender, comorbid conditions, SARS-CoV-2 lineage, and vaccination status. Results Out of 1501 COVID-19-related hospitalizations, 163 (10.9%) had documented coinfections with 44/163 [27%] involving SARS-COV-2 plus ≥2 other respiratory viruses. The majority of SARS-CoV-2 monoinfections (1176/1501, 87.9%) and coinfections (139/163, 85.3%) belonged to the Omicron era (Figure A). RSV (66/163, 40.5%) and Enterovirus/rhinovirus (61/163, 37.4%) coinfections were the most common. Coinfection cases were significantly younger than monoinfection cases (median age 1.2 [IQR:0.3-3.3] vs 1.6 [IQR:0.3-7.0] years, p=0.04). Overall, severe disease was more common among cases with any coinfection (38.0%) than SARS-CoV-2 monoinfection (25.7%; adjusted risk ratio 1.45, 95% confidence interval 1.17-1.80) (Figure B). In particular, we observed that severe outcomes were significantly higher in SARS-CoV-2 coinfections compared to monoinfections during the Omicron era (Figure C-D). Overall, 26/61 (42.6%) Enterovirus/Rhinovirus and 20/66 (30.3%) RSV coinfections were associated with severe outcomes. Conclusion Children with documented coinfections had more severe respiratory disease compared to SARS-COV-2 monoinfections. However, children with severe COVID-19 may have been more likely tested for multiple viruses, leading to a risk of underestimation of coinfections among children with milder disease. Further work is needed to assess how different virus coinfections may affect children and which, if any, may be a predominant driver of disease severity. 1Severe disease was defined as intensive care, ventilatory, or hemodynamic support requirements, organ system complications, or death. 2Lineage was first assigned based on available genetic sequencing data. If missing, lineage was imputed based on the dominant circulating lineage at the provincial level according to the GISAID database.