Map-Based Cloning and Characterization of a Major QTL Gene, FfR1, Which Confers Resistance to Rice Bakanae Disease.

Bakanae disease (BD), caused by the fungal pathogen Fusarium fujikuroi, is a serious threat to rice production worldwide. Breeding elite rice varieties resistant to BD requires the identification of resistance genes. Previously, we discovered a resistant quantitative trait locus (QTL), qFfR1, in a Korean japonica rice variety, Nampyeong. In this study, we fine-mapped qFfR1 with a Junam*4/Nampyeong BC3F3 population and delimited its location to a 37.1 kb region on chromosome 1. Complementation experiments with seven candidate genes in this region revealed that OsI_02728 is the gene for qFfR1. This gene encodes a protein with a typical leucine-rich repeat (LRR) receptor-like protein structure. RNA-sequencing-based transcriptomic analysis revealed that FfR1 induces the transcription of defense genes, including lignin and terpenoid biosynthesis genes, pathogenesis-related genes, and thionin genes. These results may facilitate investigations into the molecular mechanisms underlying BD resistance, including molecular patterns of Fusarium fujikuroi interacting with FfR1 and players working in signal transduction pathways downstream of FfR1, and the breeding of new BD-resistant varieties by providing a BD resistance gene with its precise selection marker. This will contribute to efficient control of BD, which is becoming more prevalent according to temperature rises due to climate change.

Correction to: Supercooling preservation technology in food and biological samples: a review focused on electric and magnetic field applications.

[This corrects the article DOI: 10.1007/s10068-020-00750-6.].

Selective Detection of Escherichia coli K12 and Staphylococcus aureus in Mixed Bacterial Communities Using a Single-Walled Carbon Nanotube (SWCNT)-Functionalized Electrochemical Immunosensor with Dielectrophoretic Concentration.

An electrochemical immunosensor has been developed for the rapid detection and identification of potentially harmful bacteria in food and environmental samples. This study aimed to fabricate a microwire-based electrochemical immunosensor (MEI sensor) for selective detection of Escherichia coli and Staphylococcus aureus in microbial cocktail samples using dielectrophoresis (DEP)-based cell concentration. A gold-coated tungsten microwire was functionalized by coating polyethylenimine, single-walled carbon nanotube (SWCNT) suspension, streptavidin, biotinylated antibodies, and then bovine serum albumin (BSA) solutions. Double-layered SWCNTs and 5% BSA solution were found to be optimized for enhanced signal enhancement and nonspecific binding barrier. The selective capture of E. coli K12 or S. aureus cells was achieved when the electric field in the bacterial sample solution was generated at a frequency of 3 MHz and 20 Vpp. A linear trend of the change in the electron transfer resistance was observed as E. coli concentrations increased from 5.32 × 102 to 1.30 × 108 CFU/mL (R2 = 0.976). The S. aureus MEI sensor fabricated with the anti-S. aureus antibodies also showed an increase in resistance with concentrations of S. aureus (8.90 × 102-3.45 × 107 CFU/mL) with a correlation of R2 = 0.983. Salmonella typhimurium and Listeria monocytogenes were used to evaluate the specificity of the MEI sensors. The functionalization process developed for the MEI sensor is expected to contribute to the sensitive and selective detection of other harmful microorganisms in food and environmental industries.

Real-World Outcomes of Immunotherapy in Second- or Later-Line Non-Small Cell Lung Cancer with Actionable Genetic Alterations.

INTRODUCTION: While the efficacy of immune checkpoint inhibitors (ICIs) in treating non-small cell lung cancer (NSCLC) patients with actionable genetic alterations (AGAs) is modest, certain patients demonstrate improved survival. Thus, this study aimed to evaluate the benefits of ICIs in NSCLC patients with diverse AGAs and verify the predictive biomarkers of ICI efficacy. METHODS: From January 2018 to July 2022, this study compared the progression-free survival (PFS) of NSCLC patients with different AGAs treated with ICI monotherapy as second- or later-line therapy at Samsung Medical Center. To ascertain the predictors of ICIs efficacy, we adjusted ICIs' effects on PFS in terms of clinical and molecular biomarkers. RESULTS: EGFR (46.0%) was the most prevalent mutation in 324 patients. In multivariate analysis, PD-L1 positivity (tumor proportion score (TPS) ≥ 1%) (HR = 0.41) and the use of steroids for immune-related adverse events (HR = 0.46) were positive factors for ICI therapy in the AGAs group. Co-existing mutation of STK11 with KRAS mutation (HR = 4.53) and TP53 with MET mutation (HR = 9.78) was negatively associated with survival. CONCLUSIONS: The efficacy of ICI treatment varied across AGA subtypes, but patients with KRAS, MET, and BRAF mutations demonstrated relatively long-duration benefits of ICI therapy. PD-L1 was a significant positive predictive biomarker in all AGA groups.

QTL Mapping of Tiller Number in Korean Japonica Rice Varieties.

Tiller number is an important trait associated with yield in rice. Tiller number in Korean japonica rice was analyzed under greenhouse conditions in 160 recombinant inbred lines (RILs) derived from a cross between the temperate japonica varieties Odae and Unbong40 to identify quantitative trait loci (QTLs). A genetic map comprising 239 kompetitive allele-specific PCR (KASP) and 57 cleaved amplified polymorphic sequence markers was constructed. qTN3, a major QTL for tiller number, was identified at 132.4 cm on chromosome 3. This QTL was also detected under field conditions in a backcross population; thus, qTN3 was stable across generations and environments. qTN3 co-located with QTLs associated with panicle number per plant and culm diameter, indicating it had pleiotropic effects. The qTN3 regions of Odae and Unbong40 differed in a known functional variant (4 bp TGTG insertion/deletion) in the 5' UTR of OsTB1, a gene underlying variation in tiller number and culm strength. Investigation of variation in genotype and tiller number revealed that varieties with the insertion genotype had lower tiller numbers than those with the reference genotype. A high-resolution melting marker was developed to enable efficient marker-assisted selection. The QTL qTN3 will therefore be useful in breeding programs developing japonica varieties with optimal tiller numbers for increased yield.

The application of computer vision systems in meat science and industry - A review.

Computer vision systems (CVS) are applied to macro- and microscopic digital photographs captured using digital cameras, ultrasound scanners, computer tomography, and wide-angle imaging cameras. Diverse image acquisition devices make it technically feasible to obtain information about both the external features and internal structures of targeted objects. Attributes measured in CVS can be used to evaluate meat quality. CVS are also used in research related to assessing the composition of animal carcasses, which might help determine the impact of cross-breeding or rearing systems on the quality of meat. The results obtained by the CVS technique also contribute to assessing the impact of technological treatments on the quality of raw and cooked meat. CVS have many positive attributes including objectivity, non-invasiveness, speed, and low cost of analysis and systems are under constant development an improvement. The present review covers computer vision system techniques, stages of measurements, and possibilities for using these to assess carcass and meat quality.

A single-walled carbon nanotubes-based electrochemical impedance immunosensor for on-site detection of Listeria monocytogenes.

Real-time and sensitive detection of pathogenic bacteria in food is in high demand to ensure food safety. In this study, a single-walled carbon nanotubes (SWCNTs)-based electrochemical impedance immunosensor for on-site detection of Listeria monocytogenes (L. monocytogenes) was developed. A gold-plated wire was functionalized using polyethylenimine (PEI), SWCNTs, streptavidin, biotinylated L. monocytogenes antibodies, and bovine serum albumin (BSA). A linear relationship (R2  = 0.982) between the electron transfer resistance measurements and concentrations of L. monocytogenes within the range of 103 -108 CFU/ml was observed. In addition, the sensor demonstrated high selectivity towards the target in the presence of other bacterial cells such as Salmonella Typhimurium and Escherichia coli O157:H7. To facilitate the demand for on-site detection, the sensor was integrated into a smartphone-controlled biosensor platform, consisting of a compact potentiostat device and a smartphone. The signals from the proposed platform were compared with a conventional potentiostat using the immunosensor interacted with L. monocytogenes (103 -105 CFU/ml). The signals obtained with both instruments showed high consistency. Recovery percentages of lettuce homogenate spiked with 103 , 104 , and 105 CFU/ml of L. monocytogenes obtained with the portable platform were 90.21, 90.44, and 93.69, respectively. The presented on-site applicable SWCNT-based immunosensor platform was shown to have a high potential to be used in field settings for food and agricultural applications. PRACTICAL APPLICATION: The developed immunosensor was developed for on-site detection of L. monocytogenes. The limit of detection of the sensor was 103 CFU/ml with a detection time of 10 min. In order to facilitate the requirements for effective on-site screening for food safety, the sensor was integrated into a smartphone-controlled platform, so that the bio-molecular interactions were converted into impedance signals and transmitted wirelessly to a smartphone by a hand-held EIS transducer.

Application of Supercooling for the Enhanced Shelf Life of Asparagus (Asparagus officinalis L.).

Freezing extends the shelf-life of food by slowing down the physical and biochemical reactions; however, ice crystal formation can result in irreversible damage to the cell's structure and texture. Supercooling technology has the potential to preserve the original freshness of food without freezing damage. In this study, fresh asparagus was preserved in a supercooled state and its quality changes such as color, weight loss, texture, chlorophyll and anthocyanin content, and enzymatic activities (superoxide dismutase and catalase) were evaluated. The asparagus samples were successfully supercooled at -3 °C with the combination treatment of pulsed electric field (PEF) and oscillating magnetic field (OMF), and the supercooled state was maintained for up to 14 days. Asparagus spears preserved in the supercooled state exhibited lower weight loss and higher levels of quality factors in comparison to the frozen and refrigerated control samples.

Analysis of the Temperature Distribution in a Refrigerated Truck Body Depending on the Box Loading Patterns.

The main purpose of cold chain is to keep the temperature of products constant during transportation. The internal temperature of refrigerated truck body is mainly measured with a temperature sensor installed at the hottest point on the body. Hence, the measured temperature cannot represent the overall temperature values of transported products in the body. Moreover, the airflow pattern in the refrigerated body can vary depending on the arrangement of loaded logistics, resulting temperature differences between the transported products. In this study, the airflow and temperature change in the refrigerated body depending on the loading patterns of box were analyzed using experimental and numerical analysis methods. Ten different box loading patterns were applied to the body of 0.5 ton refrigerated truck. The temperatures inside boxes were measured depending on the loading patterns. CFD modeling with two different turbulence models (k-ε and SST k-ω) was developed using COMSOL Multiphysics for predicting the temperatures inside boxes loaded with different patterns, and the predicted data were compared to the experimental data. The k-ε turbulence model showed a higher temperature error than the SST k-ω model; however, the highest temperature point inside the boxes was almost accurately predicted. The developed model derived an approximate temperature distribution in the boxes loaded in the refrigerated body.

Supercooling preservation technology in food and biological samples: a review focused on electric and magnetic field applications.

Freezing has been widely recognized as the most common process for long-term preservation of perishable foods; however, unavoidable damages associated with ice crystal formation lead to unacceptable quality losses during storage. As an alternative, supercooling preservation has a great potential to extend the shelf-life and maintain quality attributes of fresh foods without freezing damage. Investigations for the application of external electric field (EF) and magnetic field (MF) have theorized that EF and MF appear to be able to control ice nucleation by interacting with water molecules in foods and biomaterials; however, many questions remain open in terms of their roles and influences on ice nucleation with little consensus in the literature and a lack of clear understanding of the underlying mechanisms. This review is focused on understanding of ice nucleation processes and introducing the applications of EF and MF for preservation of food and biological materials.

A Nanoengineered Stainless Steel Surface to Combat Bacterial Attachment and Biofilm Formation.

Nanopatterning and anti-biofilm characterization of self-cleanable surfaces on stainless steel substrates were demonstrated in the current study. Electrochemical etching in diluted aqua regia solution consisting of 3.6% hydrogen chloride and 1.2% nitric acid was conducted at 10 V for 5, 10, and 15 min to fabricate nanoporous structures on the stainless steel. Variations in the etching rates and surface morphologic characteristics were caused by differences in treatment durations; the specimens treated at 10 V for 10 min showed that the nanoscale pores are needed to enhance the self-cleanability. Under static and realistic flow environments, the populations of Escherichia coli O157:H7 and Salmonella Typhimurium on the developed features were significantly reduced by 2.1-3.0 log colony-forming unit (CFU)/cm2 as compared to bare stainless steel (p < 0.05). The successful fabrication of electrochemically etched stainless steel surfaces with Teflon coating could be useful in the food industry and biomedical fields to hinder biofilm formation in order to improve food safety.

Quality Retention of Fresh Tuna Stored Using Supercooling Technology.

The present study was focused on the investigation of physiochemical changes in tuna subjected to a novel supercooling preservation, which was assisted using a combination of pulsed electric fields (PEF) and oscillating magnetic fields (OMF). Fresh tuna fillets were stored without freezing at -3.2 °C for 8 days. The electrochemical impedance spectroscopy (EIS) parameter Py indicated that there was a significant difference between the frozen-thawed samples (36.3%) and fresh (46.6%) and supercooled (45.9%) samples, indicating that cell damage from ice crystal growth did not occur in the supercooled tuna sample. The microstructure observation and drip loss measurement further confirmed that the ice crystal damage was present in frozen tuna, whereas no cellular damage was found in the supercooled samples. The EIS proved its ability to distinguish between tuna samples that were frozen or chilled (i.e., refrigerated and supercooled) during storage; however, it was less sensitive in detecting the extent of spoilage. Instead, the K-value was used to evaluate tuna freshness, and the measured K-values of the refrigerated, supercooled, and frozen tuna samples after 8 days of storage were 74.3%, 26.4%, and 19.9%, respectively, suggesting that the supercooling treatment significantly preserved the tuna fillets fresh with the improved shelf-life when compared to conventional refrigeration.

Durable omniphobicity of oil-impregnated anodic aluminum oxide nanostructured surfaces.

Recently, various types of porous surfaces have been demonstrated for lubricant (e.g., oil) impregnated omniphobic surfaces. However, the retention of the lubricating liquid within the porous layer and the omniphobic durability still remain challenges. Here, the omniphobic durability of the oil-impregnated surfaces of various types of anodic aluminum oxide (AAO) nanostructures is investigated. The oil impregnation into nanoporous AAO with high porosity enhances droplet mobility by eliminating the pinning site of a contact line on the solid surface, whereas that with low porosity allows the pinning site to result in less mobility. In the cases of nanopillared AAO layers, although the oil-impregnation enhances the repellency to liquids, oil is prone to be depleted by external force such as fluid flow due to the nature of the interconnected oil through the passages between pillars, which limits the omniphobic durability. Among the various types of nanostructured AAO surfaces, the AAO with isolated pore geometry with high porosity exhibits the most durable omniphobicity for a wide range of liquids including organic liquids with low surface tensions. Moreover, the nanoporous AAO surface shows great anti-bacterial adhesion property, reducing the adhesion of bacteria (Escherichia coli K-12) up to 99.2% compared to a bare aluminum surface.

Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks.

Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.

Nanoengineered Superhydrophobic Surfaces of Aluminum with Extremely Low Bacterial Adhesivity.

Bacterial adhesion and biofilm formation on surfaces are troublesome in many industrial processes. Here, nanoporous and nanopillared aluminum surfaces were engineered by anodizing and postetching processes and made hydrophilic (using the inherent oxide layer) or hydrophobic (applying a Teflon coating) with the aim of discouraging bacterial adhesion. Adhesion of Staphylococcus aureus ATCC 12600 (Gram-positive, spherically shaped) and Escherichia coli K-12 (Gram-negative, rod-shaped) was evaluated to the nanoengineered surfaces under both static and flow conditions (fluid shear rate of 37 s-1). Compared to a nonstructured electropolished flat surface, the nanostructured surfaces significantly reduced the number of adhering colony forming units (CFUs) for both species, as measured using agar plating. For the hydrophilic surfaces, this was attributed to a decreased contact area, reducing bacterial adhesion forces on nanoporous and nanopillared surfaces to 4 and 2 nN, respectively, from 8 nN on flat surfaces. Reductions in the numbers of adhering CFUs were more marked on hydrophobic surfaces under flow, amounting to more than 99.9% and 99.4% for S. aureus and E. coli on nanopillared surfaces, respectively. Scanning electron microscopy revealed a few bacteria found on the hydrophobic nanopillared surfaces adhered predominantly to defective or damaged areas, whereas the intact area preserving the original nanopillared morphology was virtually devoid of adhering bacteria. The greater decrease in bacterial adhesion to hydrophobic nanopillared surfaces than to hydrophilic or nanoporous ones is attributed to effective air entrapment in the three-dimensional pillar morphology, rendering them superhydrophobic and slippery, in addition to providing a minimized contact area for bacteria to adhere to.

Simultaneous detection of E. coli K12 and S. aureus Using a Continuous Flow Multijunction Biosensor.

Rapid detection and identification of potentially harmful bacteria is ideal for food manufacturers to prevent foodborne illness outbreaks. Continuous monitoring method of foodborne pathogens levels and trends in food gives real-time results. Therefore, the objectives of this study were to fabricate and characterize the continuous flow multijunction biosensor for simultaneous detection of Escherichia coli K12 and Staphylococcus aureus. Junction biosensors were fabricated using gold plated tungsten wires coated with polyethylenimine and single walled carbon nanotubes. Each junction was functionalized with streptavidin and biotinylated antibodies specific to E. coli K12 and S. aureus. Then, single or 2 biosensors for each targeted analyte were connected to tubing, perpendicular to the flow direction. Pure serial diluted samples of E. coli K12 and S. aureus and microbial cocktail samples were continuously pumped at a 0.0167 mL/s into the detection zone. Changes in the electric current by biorecognition reactions between antibody and antigens were calculated. The developed junction sensor coupled with the fluidic channel showed the enhancement of the electric signal responses for detection of E. coli K12, compared to the stationary sensor. A linear regression was observed for both the E. coli and S. aureus functionalized array sensors in the detection range of 10(2) to 10(5) CFU/mL. Multiplexed detection of bacteria at the sensing levels as low as 10(2) CFU/mL for E. coli K12 and S. aureus was achieved within 2 min. Therefore, the continuous flow multijunction biosensor shows potential for rapid and continuous multiplexed detection of foodborne pathogens.

Rapid detection of multiple foodborne pathogens using a nanoparticle-functionalized multi-junction biosensor.

Real-time identification of multiple bacterial pathogens in food is urgently needed to ensure food safety. Although rapid and sensitive detection methods offering simplicity, accuracy, and multiplexity are highly desirable for industrial food applications, the development of a biosensor that meets all criteria remains a challenge. In this study, a single walled carbon nanotube- (SWCNT) based multi-junction sensor was designed for potential multiplexed detection of foodborne pathogens. Gold tungsten wires (Ø: 50 µm) coated with polyethylenimine (PEI) and SWCNTs were aligned to form a 2 × 2 junction array, functionalized with streptavidin and biotinylated antibodies specific for Escherichia coli K-12 and Staphylococcus aureus. Electric current (I) measurements in response to target binding events in pure serial diluted samples of E. coli and S. aureus at each junction within the 2 × 2 array were monitored to create calibration curves. An inverse correlation between I signals and bacterial concentrations was observed. Changes in I (∆I) were also calculated to reduce background noise and emphasize the SWCNT-based sensor's response to the biorecognition reactions between antibody and antigens. A linear regression was observed for both the E. coli and S. aureus functionalized array sensors, R(2)=0.978 and R(2)=0.992, in range of 10(2)-10(5)CFU/mL. The calibration curves were used to evaluate the sensor's multiplexing capabilities to detect E. coli and S. aureus in 10 µL and 100 µL batch microbial cocktail samples.Isignal responses exhibited similar measurement trends indicating that the developed SWCNT-based multi-junction biosensor has potential for sensitive, simple, and multiplexed applications.

Electrochemical impedance spectroscopy as an alternative to determine dielectric constant of potatoes at various moisture contents.

The dielectric (DE) properties, specifically the DE constant (ε') and loss factor (ε''), were measured for vacuum-dried and freeze-dried potato samples at a microwave frequency of 2.45 GHz over a range of different moisture contents (MCs) using a DE probe and also a 2-probe electrochemical impedance spectroscopy (EIS). Third-order polynomial models (ε' = f1(MC); and ε'' = f2(MC)) at room temperature were developed for regression analysis. Additionally, at various temperatures (T), biphasic 3rd-order polynomial models (ε' = f1(MC, T); and ε'' = f2(MC, T)) were obtained to determine ε' and ε'' as a function of MC and T using measured data. The vacuum-dried potato sample showed a good fitness of ε' and ε'' (R² = 0.95 and 0.96, respectively) to the regression model with the range of MCs from 18% to 80% (w/w), while the freeze-dried potato sample showed a good fitness of ε' and ε'' to the 1st-phase regression model with MC < 50% w/w (R² = 0.95 and 0.96, respectively) and the 2nd-phase regression model with MC > 50% w/w (R² = 0.94 to 0.96). EIS measurements were also used to obtain correlation impedances for ε' and ε'' determined by the DE probe method. The resulted regression analysis meets the demands for simple, rapid, and accurate assessment for transient values of ε' and ε'' of food products during dehydration/drying processes. The EIS method was verified to be a successful alternative to direct measurements of ε' and ε''.

Single walled carbon nanotube-based junction biosensor for detection of Escherichia coli.

Foodborne pathogen detection using biomolecules and nanomaterials may lead to platforms for rapid and simple electronic biosensing. Integration of single walled carbon nanotubes (SWCNTs) and immobilized antibodies into a disposable bio-nano combinatorial junction sensor was fabricated for detection of Escherichia coli K-12. Gold tungsten wires (50 µm diameter) coated with polyethylenimine (PEI) and SWCNTs were aligned to form a crossbar junction, which was functionalized with streptavidin and biotinylated antibodies to allow for enhanced specificity towards targeted microbes. In this study, changes in electrical current (ΔI) after bioaffinity reactions between bacterial cells (E. coli K-12) and antibodies on the SWCNT surface were monitored to evaluate the sensor's performance. The averaged ΔI increased from 33.13 nA to 290.9 nA with the presence of SWCNTs in a 10(8) CFU/mL concentration of E. coli, thus showing an improvement in sensing magnitude. Electrical current measurements demonstrated a linear relationship (R2 = 0.973) between the changes in current and concentrations of bacterial suspension in range of 10(2)-10(5) CFU/mL. Current decreased as cell concentrations increased, due to increased bacterial resistance on the bio-nano modified surface. The detection limit of the developed sensor was 10(2) CFU/mL with a detection time of less than 5 min with nanotubes. Therefore, the fabricated disposable junction biosensor with a functionalized SWCNT platform shows potential for high-performance biosensing and application as a detection device for foodborne pathogens.

Electrochemical impedance spectroscopic technique with a functionalized microwire sensor for rapid detection of foodborne pathogens.

In this study, a label-free biosensor based on electrochemical impedance measurement followed by dielectrophoretic force and antibody-antigen interaction was developed for detection and quantification of foodborne pathogenic bacteria. In our previous work, gold-tungsten wires (25 µm in diameter) were functionalized by coating with polyethyleneimine-streptavidin-anti-Escherichia coli antibodies to improve sensing specificity, and fluorescence intensity measurement was employed to quantify bacteria captured by the sensor. The focus of this research is to evaluate the performance of the developed biosensor by monitoring the changes of electron-transfer resistance (ΔR(et)) of the microwire after the bioaffinity reaction between bacterial cells and antibodies on its surface as an alternative quantification technique to fluorescence microscopy. Electrochemical impedance spectroscopy (EIS) has been used to detect and validate the resistance changes in a conventional three-electrode system in which [Fe(CN)6³â»]/[Fe(CN)64⁻] served as the redox probe. The impedance data demonstrated a linear relationship between the increments of ΔR(et) and the logarithmic concentrations of E. coli suspension in the range of 10³-108 CFU/mL. In addition, there were little changes of ΔR(et) when the sensor worked with Salmonella, which clearly evidenced the sensing specificity to E. coli. EIS was proven to be an ideal alternative to fluorescence microscopy for enumeration of captured cells.