Risk factors for postpartum posttraumatic stress disorder after emergency admission.

BACKGROUND: Postpartum posttraumatic stress disorder (PTSD) can occur in women who give birth after emergency admission. The identification of risk factors for this condition is crucial for developing effective preventive measures. This retrospective study aimed to explore the incidence and risk factors for postpartum PTSD in women who give birth after emergency admission. METHODS: Medical records of women who gave birth after emergency admission were collected between March 2021 and April 2023. The patients' general conditions and perinatal clinical indicators were recorded. The puerperae were divided into PTSD group and control group based on symptom occurrence at six weeks postpartum. Multivariate logistic regression analysis was performed to identify risk factors. RESULTS: A total of 276 puerperae were included, with a PTSD incidence of 20.3% at six weeks postpartum. Multivariate logistic regression analysis identified emergency cesarean section (odds ratio [OR]=2.102; 95% confidence interval [CI]: 1.114-3.966, P=0.022), admission to the emergency department after midnight (12:00 AM) (OR=2.245; 95%CI: 1.170-4.305, P<0.001), and cervical dilation (OR=3.203; 95%CI: 1.670-6.141, P=0.039) as independent risk factors for postpartum PTSD. Analgesia pump use (OR= 0.500; 95%CI: 0.259-0.966, P=0.015) was found to be a protective factor against postpartum PTSD. CONCLUSION: Emergency cesarean section, admission to the emergency department after midnight, and cervical dilation were identified as independent risk factors for postpartum PTSD, while analgesic pump use was a protective factor. These findings provide insights for developing more effective preventive measures for women who give birth after emergency admission.

Photoelectrochemical sensor based on AuNPs@WO3@TpPa-1-COF for quantification of DNA methylation levels.

A "signal-off" photoelectrochemical (PEC) sensing platform has been designed for the ultrasensitive detection of DNA methylation levels and multiple methylated sites. The platform employs tungsten trioxide and TpPa-1-COF loaded by gold nanoparticle (AuNPs@WO3@TpPa-1-COF) composite material as the photoactive component and p-type reduced graphene (rGO) as an efficient quencher. The PEC signal of AuNPs@WO3@TpPa-1-COF composite is effectively quenched in the presence of p-type rGO, because p-type rGO can compete with AuNPs@WO3@TpPa-1-COF to deplete light energy and electron donors. In addition, a hybrid strand reaction (HCR) amplification strategy fixes more target DNA and then combines with rGO-modified anti-5-methylcytosine antibody to facilitate ultrasensitive DNA methylation detection. Under optimal conditions, DNA methylation can be measured within a linear concentration range of 10-14 to 10-8 M, with an exceptionally low detection limit of 0.19 fM (S/N = 3). At the same time, the platform can conduct quantitative determination of multi-site methylation, with the linear equation △I = 44.19LogA + 61.43, and the maximum number of methylation sites is 5. The sensor demonstrates high sensitivity, excellent selectivity, and satisfactory stability. Furthermore, the proposed signal-off PEC strategy was successfully employed to detect DNA methylation in spiked human serum samples, with recoveries ranging from 93.17 to 107.28% and relative standard deviation (RSD) ranging from 1.15 to 5.49%.

Transonic dislocation propagation in diamond.

The motion of line defects (dislocations) has been studied for more than 60 years, but the maximum speed at which they can move is unresolved. Recent models and atomistic simulations predict the existence of a limiting velocity of dislocation motion between the transonic and subsonic ranges at which the self-energy of dislocation diverges, though they do not deny the possibility of the transonic dislocations. We used femtosecond x-ray radiography to track ultrafast dislocation motion in shock-compressed single-crystal diamond. By visualizing stacking faults extending faster than the slowest sound wave speed of diamond, we show the evidence of partial dislocations at their leading edge moving transonically. Understanding the upper limit of dislocation mobility in crystals is essential to accurately model, predict, and control the mechanical properties of materials under extreme conditions.

A novel photoelectrochemical strategy for sequence-spot bispecific analysis of N6-methyladenosine modification based on proximity ligation-triggered cascade amplification.

N6-methyladenosine (m6A) modification as the most prevalent mammalian RNA internal modification has been considered as the invasive biomarkers in clinical diagnosis and biological mechanism researches. It is still challenged to explore m6A functions due to technical limitations on base- and location-resolved m6A modification. Herein, we firstly proposed a sequence-spot bispecific photoelectrochemical (PEC) strategy based on in situ hybridization mediated proximity ligation assay for m6A RNA characterization with high sensitivity and accuracy. Firstly, the target m6A methylated RNA could be transferred to the exposed cohesive terminus of H1 based on the special self-designed auxiliary proximity ligation assay (PLA) with sequence-spot bispecific recognition. The exposed cohesive terminus of H1 could furtherly trigger the next catalytic hairpin assembly (CHA) amplification and in situ exponential nonlinear hyperbranched hybridization chain reaction for highly sensitive monitoring of m6A methylated RNA. Compared with conventional technologies, the proposed sequence-spot bispecific PEC strategy for m6A methylation of special RNA based on proximity ligation-triggered in situ nHCR performed improved sensitivity and selectivity with a detection limit of 53 fM, providing new insights into highly sensitive monitoring m6A methylation of RNA in bioassay, disease diagnosis and RNA mechanism.

Ultrasensitive photoelectrochemical biosensor for DNA 5-methylcytosine analysis based on co-sensitization strategy combined with bridged DNA nanoprobe.

Altered DNA methylation in the form of 5-methylcytosine (5-mC) patterns is correlated with disease diagnosis, prognosis, and treatment response. Therefore, accurate analysis of 5-mC is of great significance for the diagnosis of diseases. Here, an efficient enhanced photoelectrochemical (PEC) biosensor was designed for the quantitative analysis of DNA 5-mC based on a cascaded energy level aligned co-sensitization strategy coupling with the bridged DNA nanoprobe (BDN). Firstly, Au nanoparticle/graphite phase carbon nitride/titanium dioxide (AuNPs/g-C3N4@TiO2) nanocomposite was synthesized through in situ growth of AuNPs on g-C3N4@TiO2 surface as a matrix to provide a stable background signal. Next, BDN with a high mass transfer rate synthesized from a pair of DNA tetrahedral as nanomechanical handles was used as a capture probe to bind to the target sequence. The polydopamine nanosphere was applied to load with CdTe QDs (PDANS-CdTe QDs) as a photocurrent label of 5-mC antibodies. When the 5-mC existed, a large number of PDANS-Ab-CdTe QDs were introduced to the electrode surface, the formed CdTe QDs/AuNPs/g-C3N4@TiO2 co-sensitive structure could effectively enhance the electron transfer capability and photocurrent response rate due to the effective cascade energy level arrangement, leading to a significantly enhanced photocurrent signal. The proposed PEC biosensor manifested a wide range from 10-17 M to 10-7 M and a detection limit of 2.2 aM. Meanwhile, the excellent performance indicated the practicability of the designed strategy, thus being capable of the clinical diagnosis of 5-mC.

Structure of human spermine oxidase in complex with a highly selective allosteric inhibitor.

Human spermine oxidase (hSMOX) plays a central role in polyamine catabolism. Due to its association with several pathological processes, including inflammation and cancer, hSMOX has garnered interest as a possible therapeutic target. Therefore, determination of the structure of hSMOX is an important step to enable drug discovery and validate hSMOX as a drug target. Using insights from hydrogen/deuterium exchange mass spectrometry (HDX-MS), we engineered a hSMOX construct to obtain the first crystal structure of hSMOX bound to the known polyamine oxidase inhibitor MDL72527 at 2.4 Å resolution. While the overall fold of hSMOX is similar to its homolog, murine N1-acetylpolyamine oxidase (mPAOX), the two structures contain significant differences, notably in their substrate-binding domains and active site pockets. Subsequently, we employed a sensitive biochemical assay to conduct a high-throughput screen that identified a potent and selective hSMOX inhibitor, JNJ-1289. The co-crystal structure of hSMOX with JNJ-1289 was determined at 2.1 Å resolution, revealing that JNJ-1289 binds to an allosteric site, providing JNJ-1289 with a high degree of selectivity towards hSMOX. These results provide crucial insights into understanding the substrate specificity and enzymatic mechanism of hSMOX, and for the design of highly selective inhibitors.

DNA methylation detection and site analysis by using an electrochemical biosensor constructed based on toehold-mediated strand displacement reaction.

DNA methylation has become a novel target for early diagnosis and prognosis of cancer as well as other related diseases. The accurate detection of the methylation sites of specific genes proved to be of great significance. However, the complex biological nature of clinical samples and the detection of low-abundance targets led to higher requirements for the testing technology. It has been found that by virtue of high sensitivity, rapid response, low cost, facile operation and applicability to microanalysis, electrochemical sensors have greatly contributed to the process of clinical diagnosis. In this study, a facile, rapid and highly sensitive electrochemical biosensor based on the peak current change was developed on the basis of high selectivity of toehold and greater efficiency of PNA strand displacement and used for the detection and site analysis of DNA methylation. Moreover, compared with non-methylated DNA sequences, methylated DNA sequences could be readily invaded by PNA probes, thereby resulting in the strand displacement and significant electrical signals. Therefore, methylation of cytosine sites was primarily analyzed based on electrical signals. Strand displacement by the target DNA sequences with different methylated sites can lead to substantial changes of strand displacement efficiency. As a result, the methylation sites can be analyzed on the basis of corresponding peak current response relation. This method has a detection limit of 0.075 pM and does not involve various complicated steps such as bisulfite treatment, enzyme digestion and PCR amplification. Indeed, one detection cycle can be completed in 60 min. The proposed technology might exhibit great potential in early clinical diagnosis and risk assessment of cancers and related diseases.

Calreticulin enhances gastric cancer metastasis by dimethylating H3K9 in the E-cadherin promoter region mediating by G9a.

The latest study shows that gastric cancer (GC) ranked the fifth most common cancer (5.6%) with over 1 million estimated new cases annually and the fourth most common cause of cancer death (7.7%) globally in 2020. Metastasis is the leading cause of GC treatment failure. Therefore, clarifying the regulatory mechanisms for GC metastatic process is necessary. In the current study, we discovered that calreticulin (CALR) was highly expressed in GC tissues and related to lymph node metastasis and patient's terrible prognosis. The introduction of CALR dramatically promoted GC cell migration in vitro and in vivo, while the repression of CALR got the opposite effects. Cell migration is a functional consequence of the epithelial-mesenchymal transition (EMT) and is related to adhesion of cells. Additionally, we observed that CALR inhibition or overexpression regulated the expression of EMT markers (E-cadherin, ZO-1, Snail, N-cadherin, and ZEB1) and cellular adhesive moleculars (Fibronectin, integrin ß1and MMP2). Mechanistically, our data indicated that CALR could mediate DNA methylation of E-cadherin promoter by interacting with G9a, a major euchromatin methyltransferase responsible for methylation of histone H3 on lysine 9(H3K9me2) and recruiting G9a to the E-cadherin promoter. Knockdown of G9a in CALR overexpressing models restored E-cadherin expression and blocked the stimulatory effects of CALR on GC cell migration. Taken together, these findings not only reveal critical roles of CALR medicated GC metastasis but also provide novel treatment strategies for GC.

Effects of Sevoflurane and Propofol on Posttraumatic Stress Disorder After Emergency Trauma: A Double-Blind Randomized Controlled Trial.

Objective: Posttraumatic stress disorder (PTSD) is a frequent and disabling consequence of traumatic events. A previous study found that early use of propofol was a potential risk factor for PTSD. This prospective study aimed to investigate the effect of propofol and sevoflurane on PTSD after emergency surgery in trauma patients. Methods: A total of 300 trauma patients undergoing emergency surgery were randomly divided into two groups and anesthetized with propofol and/or sevoflurane. Perioperative clinical data were collected. The incidence of PTSD was evaluated with the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) in the two groups 1 month after the operation. The relevance of the injury time and CAPS-5 scores was assessed by Spearman correlation analysis. Logistic regression analysis was used to analyze the risk factors for PTSD. Results: The incidence of PTSD in the propofol group was higher than that in the sevoflurane group 1 month postoperatively (23.2 vs. 12.2%, P = 0.014). The injury time was negatively correlated with the CAPS-5 score in the propofol group (r = -0.226, P < 0.001). In the logistic regression analysis, the utilization of propofol was an independent risk factor for PTSD (P = 0.017). Conclusion: Early use of propofol general anesthesia in emergency surgery for trauma patients may increase the risk of PTSD. Clinical Trial Registration: www.chictr.org.cn, identifier: ChiCTR2100050202.

Universal scaling laws of keyhole stability and porosity in 3D printing of metals.

Metal three-dimensional (3D) printing includes a vast number of operation and material parameters with complex dependencies, which significantly complicates process optimization, materials development, and real-time monitoring and control. We leverage ultrahigh-speed synchrotron X-ray imaging and high-fidelity multiphysics modeling to identify simple yet universal scaling laws for keyhole stability and porosity in metal 3D printing. The laws apply broadly and remain accurate for different materials, processing conditions, and printing machines. We define a dimensionless number, the Keyhole number, to predict aspect ratio of a keyhole and the morphological transition from stable at low Keyhole number to chaotic at high Keyhole number. Furthermore, we discover inherent correlation between keyhole stability and porosity formation in metal 3D printing. By reducing the dimensions of the formulation of these challenging problems, the compact scaling laws will aid process optimization and defect elimination during metal 3D printing, and potentially lead to a quantitative predictive framework.

Erratum: Cardioprotective effects of triiodothyronine supplementation against ischemia reperfusion injury by preserving calcium cycling proteins in isolated rat hearts.

[This corrects the article DOI: 10.3892/etm.2019.8114.].

3D matrixed DNA self-nanocatalyzer as electrochemical sensitizers for ultrasensitive investigation of DNA 5-methylcytosine.

DNA methylation plays an important role in a variety of human diseases. Thus, accurately analyze 5-methylcytosine in different DNA segments is of great significance. Herein, we proposed a novel 3D matrixed DNA self-nanocatalyzer via gold nanoparticles (AuNPs) supporting DNA self-hybridization with hemin as biomimetic enzyme and methylene blue (MB) as electrochemical mediator, which was employed as an efficient electrochemical sensitizer for the ultrasensitive bioassay of DNA 5-methylcytosine. Meanwhile, the AuNPs, graphitic carbon nitride (g-C3N4) and reduced graphene oxide (rGO) was prepared as AuNPs/g-C3N4@rGO nanocomposites to coat on the electrode surface to immobilize the capture hairpin DNA (CH). In the presence of target DNA with 5-methylcytosine, the target DNA could hybridize with CH via the hyperstable triple-helix formation. Based on the specific biorecognition between biotin and streptavidin and immune recognition between anti-5-methylcytosine antibodies and 5-methylcytosine sites on the target DNA, the 3D matrixed DNA self-nanocatalyzer could be captured onto the electrode surface to generate an amplified electrochemical signal related to the concentration of 5-methylcytosine. Under the optimal conditions, the proposed strategy performed a linear range from 10-17 M to 10-8 M with a detection limit of 8.6 aM. Remarkably, this strategy could be expanded easily to various biomarkers, including protein, DNA, phosphorylation and glycosylation, providing a promising strategy for clinical diagnosis and mechanism investigation of various diseases.

A sensitive electrochemical strategy via multiple amplification reactions for the detection of E. coli O157: H7.

The sensitive and efficient strategy remains a central challenge for early diagnosis of pathogenic bacteria. Herein, an ultrasensitive electrochemical biosensor was proposed based on the multiple amplification strategy via the 3D DNA walker, rolling circle amplification (RCA) and hybridization chain reaction (HCR) for the accurate detection of Escherichiacoli O157:H7 (E. coli O157:H7). Firstly, the target sequence extracted from E. coli O157:H7 was transformed and amplified by the DNA walker firstly. Subsequently, a large number of transformed nucleic acid sequences were amplified by the RCA reaction. And then, the progress of HCR was triggered by every fragment in RCA products to form a long double-stranded DNA sequence to immobilize electrochemical indicators, generating a significantly enhanced electrochemical signal. As expected, a high sensitivity with a detection limit of 7 CFU/mL was achieved based on the proposed multiple amplification strategy, which is superior to most current methods for E. coli O157: H7 assay. The multiple amplification strategy could be readily expanded for the detection of various pathogenic bacteria, providing a new approach for early diagnosis of pathogenic microorganisms or other diseases.

A novel fluorescent biosensor based on dendritic DNA nanostructure in combination with ligase reaction for ultrasensitive detection of DNA methylation.

BACKGROUND: DNA methylation detection is indispensable for the diagnosis and prognosis of various diseases including malignancies. Hence, it is crucial to develop a simple, sensitive, and specific detection strategy. METHODS: A novel fluorescent biosensor was developed based on a simple dual signal amplification strategy using functional dendritic DNA nanostructure and signal-enriching polystyrene microbeads in combination with ligase detection reaction (LDR). Dendritic DNA self-assembled from Y-DNA and X-DNA through enzyme-free DNA catalysis of a hairpin structure, which was prevented from unwinding at high temperature by adding psoralen. Then dendritic DNA polymer labeled with fluorescent dye Cy5 was ligated with reporter probe into a conjugate. Avidin-labeled polystyrene microbeads were specifically bound to biotin-labeled capture probe, and hybridized with target sequence and dendritic DNA. LDR was triggered by adding Taq ligase. When methylated cytosine existed, the capture probe and reporter probe labeled with fluorescent dye perfectly matched the target sequence, forming a stable duplex to generate a fluorescence signal. However, after bisulfite treatment, unmethylated cytosine was converted into uracil, resulting in a single base mismatch. No fluorescence signal was detected due to the absence of duplex. RESULTS: The obtained dendritic DNA polymer had a large volume. This method was time-saving and low-cost. Under the optimal experimental conditions using avidin-labeled polystyrene microbeads, the fluorescence signal was amplified more obviously, and DNA methylation was quantified ultrasensitively and selectively. The detection range of this sensor was 10-15 to 10-7 M, and the limit of detection reached as low as 0.4 fM. The constructed biosensor was also successfully used to analyze actual samples. CONCLUSION: This strategy has ultrasensitivity and high specificity for DNA methylation quantification, without requiring complex processes such as PCR and enzymatic digestion, which is thus of great value in tumor diagnosis and biomedical research.

Cardioprotective effects of triiodothyronine supplementation against ischemia reperfusion injury by preserving calcium cycling proteins in isolated rat hearts.

Hypothyroidism is associated with profound left ventricular dysfunction. Triiodothyronine (T3) supplementation may improve cardiac function after ischemic reperfusion (I/R) injury. In the present study, the effect of T3 on major calcium cycling proteins and high-energy phosphate content during I/R was evaluated. Isolated perfused rat hearts were divided into 5 groups: Sham Control (Sham, n=10), Control (n=8), T3 10 nM (T3-10, n=10), T3 25 nM (T3-25, n=10) and T3 50 nM (T3-50, n=10). T3 was administrated for 60 min before 30 min of ischemia and 120 min of reperfusion. The protein contents of Ca2+-release channels (RyR2), Ca2+-adenosine triphosphatase (SERCA2a), phospholamban (PLB), sarcolemmal Ca2+-adenosine triphosphatase (PMCA) and sodium-calcium exchanger (NCX), as well as the high-energy phosphate content in heart tissues were measured by western blot analysis. The results revealed that T3 improved the contractile recovery (left ventricular developed pressure; +dP/dt, -dP/dt) after I/R. Western blotting assays demonstrated that I/R depressed the contents of RYR2, SERCA2a and phosphorylated RYR2 and PLB; there were no effects on the contents of PLB, PMCA and NCX. T3 reversed I/R-induced degradation of RyR2 and SERCA2a, restored the phosphorylation of RyR2 and PLB, and preserved the high-energy phosphate contents of ATP and creatine phosphate. T3 supplementation protected the heart against I/R injury via the preservation of Ca2+-cycling proteins and high-energy phosphate content.

An electrochemical DNA biosensor analytic technique for identifying DNA methylation specific sites and quantify DNA methylation level.

We herein developed a novel electrochemical biosensor to detect DNA methylation level, and to quantitatively analyze multiple methylated sites. Graphene oxide was modified with anti-5-methylcytosine antibody to specifically bind CpG methylation sites, and horseradish peroxidase (HRP)-labeled IgG secondary antibody was bound to the former antibody. In buffer containing H2O2 and hydroquinone, HRP-IgG catalyzed the oxidation of hydroquinone into benzoquinone over H2O2, thereby generating electrochemical reduction signals. The number of 5-methylcytosine was directly proportional to current signal, thereby allowing accurate quantification of methylation level. We also analyzed monomethylated target sequences with different sites. After different methylated sites were captured by the probe, the steric hindrance differences between -CH3 hydrophobic sphere and the electrode surface were induced. The peak current decreased with reducing distance from the electrode surface, so DNA methylation sites were identified by measuring corresponding peak current responses. With a low detection limit (1 fM), this DNA biosensor was suitable for ultrasensitive DNA methylation detection. The linear detection range was 10-15 M to 10-8 M. Meanwhile, this method had high specificity, stability and repeatability, thus being widely applicable to the clinical detection of DNA methylation.

Electrochemical Biosensor for DNA Methylation Detection through Hybridization Chain-Amplified Reaction Coupled with a Tetrahedral DNA Nanostructure.

DNA methylation is a key factor in the pathogenesis of gene expression diseases or malignancies. Thus, it has become a significant biomarker for the diagnosis and prognosis of these diseases. In this paper, we designed an ultrasensitive and specific electrochemical biosensor for DNA methylation detection. The platform consisted of stem-loop-tetrahedron composite DNA probes anchoring at a Au nanoparticle-coated gold electrode, a restriction enzyme digestion of HpaII, and signal amplification procedures including electrodeposition of Au nanoparticles, hybridization chain reaction, and horseradish peroxidase enzymatic catalysis. Under optimal conditions, the design showed a broad dynamic range from 1 aM to 1 pM and a detection limit of about 0.93 aM. The approach also showed ideal specificity, repeatability, and stability. The recovery test demonstrated that the design is a promising platform for DNA methylation detection under clinical circumstances and could meet the need for cancer diagnosis.

An electrochemical strategy with tetrahedron rolling circle amplification for ultrasensitive detection of DNA methylation.

Sensitive and specific detection of DNA methylation in genomic DNA is imperative for rapid epigenetic evaluations. Here, a novel sensitive electrochemical strategy was developed for ultrasensitive detection of DNA methylation in genomic DNA via padlock probe primer generating rolling circle amplification (RCA). Typically, after bisulfite treatment of methylated DNA, the methylation-specific linear padlock is only circularized in the presence of methylated DNA and subsequently serves as a template containing a DNA tetrahedron for RCA. The DNA tetrahedron is utilized as a nanocarrier that can be immobilized on a gold electrode to generate RCA product to load hemin, an iron-containing porphyrin with chlorine, forming the G-quadruplex as a horseradish peroxidase like DNAzyme, which reduces methylene blue (MB) in the presence of H2O2 to yield a distinct current signal. Using the developed DNAzyme with the RCA signal amplification strategy, the DNA biosensor can achieve a detection limit as low as 0.1 fM for the ultrasensitive electrochemical detection of methylated DNA sequence with a detection range from 10-15 M to 10-9 M. At the same time, the satisfactory specificity, reproducibility, stability and recovery performances indicated its satisfied potentials for clinical diagnosis. Most importantly, this method can be further applied to analyse other genomic DNA also.

Oxiracetam or fastigial nucleus stimulation reduces cognitive injury at high altitude.

BACKGROUND: Cognitive impairment is common in people travelling to high altitude. Oxiracetam and electrical stimulation of cerebellar fastigial nucleus may have beneficial impacts. This study was to investigate the effects of preconditioning with Oxiracetam or fastigial nucleus stimulation (FNS) on cognitive decline following the ascension to high altitude. METHODS: The study was conducted on 60 male military voluntary members who were divided into control group, Oxiracetam group, and fastigial nucleus stimulation group. Transcranial doppler sonography, auditory evoked potential, electroencephalogram (EEG), and cognitive assessments were performed. RESULTS: People could still suffer cognitive dysfunction at 4,000 m high altitude despite that they have lived at 1,800 m altitude for several years. The 4,000 m altitude environment also prolonged P300 and N200 latencies. Both Oxiracetam and FNS improved cognitive function, reduced the prolonged latencies of Event Related Potentials (P300 and N200), decreased the average velocity of brain arteries, and enhanced EEG power spectral entropy at 4,000 m altitude. CONCLUSIONS: Neurophysiological evidences suggest the underlying mechanism of cognitive impairments. Both Oxiracetam and FNS can reduce cognitive decline post arrival at high altitude. They could be a potential pretreatment method for cognitive dysfunction resulted from high altitude.

An Electrochemical Strategy using Multifunctional Nanoconjugates for Efficient Simultaneous Detection of Escherichia coli O157: H7 and Vibrio cholerae O1.

The rapid and accurate quantification of the pathogenic bacteria is extremely critical to decrease the bacterial infections in all areas related to health and safety. We have developed an electrochemical strategy for simultaneous ultrasensitive detection of E. coli O157:H7 and Vibrio cholerae O1. This approach was based on the specific immune recognition of different pathogenic bacteria by multifunctional nanoconjugates and subsequent signal amplification. By employing the proposed biosensor, the concentrations of these pathogenic bacteria could be established on a single interface in a single run with improved sensitivity and accuracy. The successful approach of the simultaneous detection and quantification of two bacteria by an electrochemical biosensor demonstrated here could be readily expanded for the estimation of a variety of other pathogenic bacteria, proteins, and nucleotides. Because of their high sensitivity, electrochemical biosensors may represent a new avenue for early diagnosis of diseases.