Highly sensitive detection of dipicolinic acid with a water-dispersible terbium-metal organic framework

Bhardwaj, Neha,Bhardwaj, Sanjeev,Mehta, Jyotsana,Kim, Ki-Hyun,Deep, Akash Elsevier 2016 Biosensors & bioelectronics Vol.86 No.-

<P><B>Abstract</B></P> <P>The sensitive detection of dipicolinic acid (DPA) is strongly associated with the sensing of bacterial organisms in food and many types of environmental samples. To date, the demand for a sensitive detection method for bacterial toxicity has increased remarkably. Herein, we investigated the DPA detection potential of a water-dispersible terbium-metal organic framework (Tb-MOF) based on the fluorescence quenching mechanism. The Tb-MOF showed a highly sensitive ability to detect DPA at a limit of detection of 0.04nM (linear range of detection: 1nM to 5µM) and also offered enhanced selectivity from other commonly associated organic molecules. The present study provides a basis for the application of Tb-MOF for direct, convenient, highly sensitive, and specific detection of DPA in the actual samples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dipicolinic acid (DPA) is an excellent indicator of bacterial infection. </LI> <LI> In this work, metal organic frameworks (MOFs) are explored as potential DPA detectors. </LI> <LI> Fluorescent detection of DPA is achieved by synthesizing the Tb-MOF ‘Tb(BTC)(H<SUB>2</SUB>O)<SUB>6</SUB>’. </LI> </UL> </P>

An overview of different strategies to introduce conductivity in metal-organic frameworks and miscellaneous applications thereof

Bhardwaj, Sanjeev K.,Bhardwaj, Neha,Kaur, Rajnish,Mehta, Jyotsana,Sharma, Amit L.,Kim, Ki-Hyun,Deep, Akash The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.31

<P>Metal-organic frameworks (MOFs) are known to possess many interesting material properties such as high specific surface area, tailorable porosity, adsorption/absorption capabilities, post-synthetic modifications, and chemical/thermal stabilities. Because of these unique features, they have been explored for the development of sensors for a variety of analytes. A large proportion of pre-existing MOF-based sensors are well suited for optical transductions due to a lack of electrical conduction in their pristine forms. Hence, the development of MOF-based electrochemical/electrical sensors requires specialized strategies through which MOFs are modified or hybridized with enhanced conductive moieties (<I>e.g.</I>, <I>via</I> doping or post synthetic modification). In this review article, we provide a comprehensive review of various synthetic and integrating strategies to improve electrical conductivity and long-range charge transport properties in MOFs. To this end, we have compiled details of different techniques that have been used to develop electrically/electrochemically active platforms for MOF-based sensing of various targets.</P>

MOF–Bacteriophage Biosensor for Highly Sensitive and Specific Detection of <i>Staphylococcus aureus</i>

Bhardwaj, Neha,Bhardwaj, Sanjeev K.,Mehta, Jyotsana,Kim, Ki-Hyun,Deep, Akash American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.39

<P>To produce a sensitive and specific biosensor for Staphylococcus aureus, bacteriophages have been interfaced with a water-dispersible and environmentally stable metal-organic framework (MOF), NH2-MIL-53(Fe). The conjugation of the MOF with bacteriophages has been achieved through the use of glutaraldehyde as cross-linker. Highly sensitive detection of S. aureus in both synthetic and real samples was realized by the proposed MOF-bacteriophage' biosensor based on the photoluminescence quenching phenomena; limit of detection (31 CFU/mL) and range of detection (40 to 4 X 10(8) CFU/mL). This is the first report exploiting the use of an MOF-bacteriophage complex for the biosensing of S. aureus. The results of our study highlight that-the proposed biosensor is more sensitive than most of the previous methods while exhibiting some advanced features like specificity) regenerability, extended range of linear 'detection, and stability for long-term storage (even at room temperature).</P>

Fluorescent nanobiosensors for the targeted detection of foodborne bacteria

Bhardwaj, Neha,Bhardwaj, Sanjeev K.,Nayak, Manoj K.,Mehta, Jyotsana,Kim, Ki-Hyun,Deep, Akash Elsevier 2017 Trends in analytical chemistry Vol.97 No.-

<P>Foodborne diseases caused by bacterial pathogens are severe threats to human health. Conventional culture based microbiologic methods for the analysis of bacterial contamination in food products are laborious, time consuming and require specific skills. Immunologic and polymerase chain reaction (PCR) based molecular methods are also costly, lack specificity, and may yield false results. As outlined in this review, fluorescent nanobiosensors have now become effective alternative tools for rapid and routine detection of foodborne bacteria. We provide an overview of the use of different fluorescent nano materials in the development of nanobiosensors with special emphasis on underlying detection principles, sensitivity, specificity, and their capability of multiplexed analysis. In summary, the diverse nanomaterials used for bacterial detection are critically analyzed with respect to their advantages and limitations for future applications in the diagnosis of foodborne bacteria. (C) 2017 Elsevier B.V. All rights reserved.</P>

Selective hydrolysis of amorphous cellulosic fines for improvement in drainage of recycled pulp based on ratios of cellulase components

Nishi K. Bhardwaj,Nishi K. Bhardwaj,Surendra P. Singh 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.22 No.-

Recycled pulp contains large amount of fines having high surface area and amorphous cellulose. Thesefines adsorb water to large extent and dewatering rate is lower compared to virgin pulp. Selectivehydrolysis of these excess ultra fines through cellulase enzymes can be utilized for enhancing thedrainage rate. The concept of monocomponent cellulase treatment of recycled pulp for improvement indrainage and the understanding whether effectiveness depends on a specific type of cellulasecomponent (endoglucanase/cellobiohydrolase) is described. The improvement of 15–23% in pulpdrainability was achieved along with better paper properties.

Water stress changes on AMF colonization, stomatal conductance and photosynthesis of Dalbergia sissoo seedlings grown in entisol soil under nursery condition

Bhardwaj Atul Kumar,Chandra K. K.,Kumar Rajesh 한국산림과학회 2023 Forest Science And Technology Vol.19 No.1

Water stress significantly impacts the plants’ physiological activity. They are influenced by the stomata and photosynthesis of the plant. The main objectives of the experiments are to determine the stomata and photosynthetic activity changes in the Dalbergia sissoo seedlings under the entisol soil in nursery conditions and the water stress conditions on AMF colonization. The plant growth characteristics and physiological activities in D. sissoo were assessed under three conditions: WW (well watering), FW (fractionated watering), and SW (stopped/no watering), with the results revealing that the FW condition has a higher mycorrhizal dependency of 24.53% than the WW condition, which is 24.37%. AMF root colonization was also higher in D. Sissoo, at 56% and 47% under FW and WW conditions. These findings highlight the significance of AMF, especially when plants are experiencing water stress. When FW was used instead of WW, the photosynthetic rate of D. sissoo and AMFþplants increased by 17.85%. AMF inoculation changed the plant’s physiological activities, resulting in a significantly higher photosynthesis rate and stomatal conductance. However, higher transpiration, intercellular CO2 concentration, and a lower leaf temperature regardless of WW or FW conditions indicate that AM positively affects physiological activities. The findings support the use of AMF in entisol soil to improve plant growth and biomass by alleviating adverse edaphic conditions.

Inclusive and exclusive measurements ofBdecays toχc1andχc2at Belle

Bhardwaj, V.,Miyabayashi, K.,Panzenbö,ck, E.,Trabelsi, K.,Frey, A.,Abdesselam, A.,Adachi, I.,Aihara, H.,Al Said, S.,Arinstein, K.,Asner, D. M.,Atmacan, H.,Aulchenko, V.,Aushev, T.,Ayad, R.,Babu, V American Physical Society 2016 Physical Review D Vol.93 No.5

<P>We report inclusive and exclusive measurements for chi(c1) and chi(c2) production in B decays. We measure B(B -> chi X-c1) = (3.03 +/- 0.05 (stat) +/- 0.24(syst)) x 10(-3) and B(B -> chi X-c2) = (0.70 +/- 0.06 (stat) +/- 0.10(syst)) x 10(-3). For the first time, chi(c2) production in exclusive B decays in the modes B-0 -> chi(c2) pi K--(+) and B-0 -> chi(c2) pi(-)pi K-+(+) has been observed, along with first evidence for the B-0 -> chi(c2) pi K--(s)0 decay mode. For chi c1 production, we report the first observation in the B+ -> chi(c1) pi(-)pi K-+(+), B-0 -> chi(c1) pi(-)pi K-+(s)0 and B-0 -> chi(c1) pi(-)pi K-+(+) decay modes. Using these decay modes, we observe a difference in the production mechanism of chi(c2) in comparison to chi(c1) in B decays. In addition, we report searches for X(3872) and chi(c1) (2P) in the B+ -> (chi(c1) pi(+)pi(-))K+ decay mode. The reported results use 772 x 10(6) B (B) over bar events collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.</P>

Tea Saponin Induces Apoptosis in HT-29 Colon Cancer Cells Via TRAIL Dependent Apoptotic Pathway

Bhardwaj JYOTI,Chaudhary NARENDRA,Hyo Jin SEO,Tai Sun SHIN,Min Yong KIM,Jong Deog KIM 한국생물공학회 2014 한국생물공학회 학술대회 Vol.2014 No.4

Transition metal oxide (Ni, Co, Fe)-tin oxide nanocomposite sensing electrodes for a mixed-potential based NO₂ sensor

Bhardwaj, Aman,Kim, In-ho,Hong, Jae-woon,Kumar, Aniket,Song, Sun-Ju Elsevier Sequoia 2019 Sensors and actuators. B Chemical Vol.284 No.-

<P><B>Abstract</B></P> <P>A mixed-potential based sensor utilizing transition metal oxide (Ni, Co, Fe)-tin oxide nanocomposite sensing electrodes are fabricated for the first time and investigated for the gas sensing performance towards the highly toxic nitrogen dioxide. The nanocomposites are synthesized by solvo-combustion route and characterized for the physical, gas sensing and electrochemical properties in a temperature range of 600–700 ℃. The sensor equipped with Fe<SUB>2</SUB>O<SUB>3</SUB>-SnO<SUB>2</SUB> (Fe:Sn = 2:1) nanocomposite sensing electrodes sintered at 1000 ℃ shows the maximum response of 60 mV towards 100 ppm NO<SUB>2</SUB> with a relatively fast response and recovery dynamics at an operating temperature of 650 ℃. The sensor also shows a linear dependence of response over the logarithm of NO<SUB>2</SUB> concentration with a sensitivity of ∼44 mV/decade. Additionally, the oxygen concentration dependence, cyclability and cross-sensitivity towards interfering gases are also investigated. Finally, the sensing mechanism and electrochemical activity of the sensing electrodes are studied using polarization curve measurement and electrochemical impedance spectroscopy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mixed-potential based sensor utilizing transition metal oxide (Ni, Co, Fe)-tin oxide nanocomposite sensing electrodes. </LI> <LI> Fe<SUB>2</SUB>O<SUB>3</SUB>-SnO<SUB>2</SUB> nanocomposite sensing electrode responded 60mV towards 100ppm NO<SUB>2</SUB> at 650 ℃. </LI> <LI> The sensitivity of the sensor was found to be 44 mV/dec. in 10-100 ppm NO<SUB>2</SUB> concentration. </LI> <LI> The sensor displayed a low oxygen conc. dependence, high selectivity and high cyclability. </LI> <LI> Sensing mechanism and key parameters determining the sensing performance are discussed in details. </LI> </UL> </P>

Recent changes of trans-boundary air pollution over the Yellow Sea: Implications for future air quality in South Korea

Bhardwaj, Piyush,Ki, Seo J.,Kim, Youn H.,Woo, Jung H.,Song, Chang K.,Park, Soon Y.,Song, Chul H. Elsevier 2019 Environmental pollution Vol.247 No.-

<P><B>Abstract</B></P> <P>The influence of air pollutants originating from the Chinese region on air quality over South Korea has been a major concern for policymakers. To investigate the inter-annual trends of the long-distance transport of air pollutants from China to South Korea, multi-year trend analysis was carried out for Aerosol Optical Depth (AOD, as a proxy of particulate matter), and CO (a water-insoluble air pollutant) and SO<SUB>2</SUB> (a partially water-soluble air pollutant), over three regions in Northeast Asia. Air pollutants are typically long-range transported from the highly polluted parts of China to South Korea through the Yellow Sea. Taking advantage of this geographical merit, we carried out the multi-year trend analysis with a special focus on the Yellow Sea region. Decreasing trends of about 5–10%, 13–17% and 55–61% during the last decade were observed in surface CO, AOD and tropospheric SO<SUB>2</SUB> columns over the North China Plain (NCP), Yellow Sea (YS), and South Korea (SK), respectively. Such decreasing trends were also found consistently during the last three, five, and seven years, indicating that the changes in pollution levels are likely in response to recent policy measures taken by the Chinese and Korean governments to improve air quality over the regions. Due to these efforts, the amounts of air pollutants transported from China to South Korea are expected to decrease in future years, to the likely rates of 1.50 ppb yr<SUP>−1</SUP>, 0.05 DU yr<SUP>−1</SUP>, and 0.56 μg m<SUP>−3</SUP> yr<SUP>−1</SUP> over the YS region for CO, SO<SUB>2</SUB>, and PM<SUB>2.5</SUB>, respectively. Given the ambitious plans recently announced by the Chinese government for the 21st meeting of Conference of Parties (COP21) and its co-control effects, the suggested percentage rates may even be conservative numbers. This analysis is expected to provide South Korean policymakers with valuable information to establish new air pollution policies in South Korea.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The decrease in air pollutants over the Yellow Sea suggested a decrease in LRT air pollutants from NCP to South Korea. </LI> <LI> Likely annual reduction rates of 1.50 ppb, 0.05 DU, and 0.56 μg/m<SUP>3</SUP> for CO, SO2, and PM<SUB>2.5</SUB> are expected over the Yellow Sea. </LI> <LI> Recent emission reductions in NCP suggested a future decrease in the LRT air pollutants from China (NCP). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>