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Bacteremia and associated bacterial sepsis are potentially fatal and occur when the host response to microbial invasion is impaired or compromised. This motivated us to develop carbonized polymer dots (CPDs

International audience; Copper/bismuth sulfide heterojunctions boost the catalytic and photoresponsive properties engendered antibacterial activity against clinically isolated multidrug-resistant bacteria and their associated biofilms.We report a one-pot facile synthesis of highly photoresponsive bovine serum albumin (BSA) templated bismuth-copper sulfide nanocomposites (BSA-BiZ/CuxS NCs, where BiZ represents in situ formed Bi2S3 and bismuth oxysulfides (BOS)). As-formed surface vacancies and BiZ/CuxS heterojunctions impart superior catalytic, photodynamic and photothermal properties. Upon near-infrared (NIR) irradiation, the BSA-BiZ/CuxS NCs exhibit broad-spectrum antibacterial activity, not only against standard multidrug-resistant (MDR) bacterial strains but also against clinically isolated MDR bacteria and their associated biofilms. The minimum inhibitory concentration of BSA-BiZ/CuxS NCs is 14-fold lower than that of BSA-CuxS NCs because their multiple heterojunctions and vacancies facilitated an amplified phototherapeutic response. As-prepared BSA-BiZ/CuxS NCs exhibited substantial biofilm inhibition (90%) and eradication (>75%) efficiency under NIR irradiation. Furthermore, MRSA-infected diabetic mice were immensely treated with BSA-BiZ/CuxS NCs coupled with NIR irradiation by destroying the mature biofilm on the wound site, which accelerated the wound healing process via collagen synthesis and epithelialization. We demonstrate that BSA-BiZ/CuxS NCs with superior antimicrobial activity and high biocompatibility hold great potential as an effective photosensitive agent for the treatment of biofilm-associated infections.

Multifunctional lanthanide-doped upconversion nanoparticles (UCNPs) have spread their wings in the fields of flexible optoelectronics and biomedical applications. One of the ongoing challenges lies in achieving UCNP-based nanocomposites, which enable a continuous-wave (CW) laser action at ultralow thresholds. Here, gold sandwich UCNP nanocomposites [gold (Au

MXenes with interesting optical and electrical properties have been attractive in biomedical applications such as antibacterial and anticancer agents, but their low photogeneration efficiency of reactive oxygen species (ROS) and poor stability are major concerns against microbial resistance.Water-dispersible single layer TiUnder NIR irradiation, the CuUpon NIR illumination, Cu

We report a one-pot facile synthesis of highly photoresponsive bovine serum albumin (BSA) templated bismuth-copper sulfide nanocomposites (BSA-BiZ/Cu

BackgroundShrimp aquaculture has suffered huge economic losses over the past decade due to the outbreak of acute hepatopancreatic necrosis disease (AHPND), which is mainly caused by the bacteriaVibrio parahaemolyticus(V. parahaemolyticus) with the virulence pVA1 plasmid, which encodes a secretory photorhabdus insect-related (Pir) toxin composed of PirA and PirB proteins. The Pir toxin mainly attacks the hepatopancreas, a major metabolic organ in shrimp, thereby causing necrosis and loss of function. The pandemic of antibiotic-resistant strains makes the impact worse.MethodsMild pyrolysis of a mixture of polysaccharide dextran 70 and the crosslinker 1,8-diaminooctane at 180 ℃ for 3 h to form carbonized nanogels (DAO/DEX-CNGs) through controlled cross-linking and carbonization. The multifunctional therapeutic CNGs inherit nanogel-like structures and functional groups from their precursor molecules.ResultsDAO/DEX-CNGs manifest broad-spectrum antibacterial activity againstVibrio parahaemolyticusresponsible for AHPND and even multiple drug-resistant strains. The polymer-like structures and functional groups on graphitic-carbon within the CNGs exhibit multiple treatment effects, including disruption of bacterial membranes, elevating bacterial oxidative stress, and neutralization of PirAB toxins. The inhibition ofVibrioin the midgut of infected shrimp, protection of hepatopancreas tissue from Pir toxin, and suppressing overstimulation of the immune system in severeV. parahaemolyticusinfection, revealing that CNGs can effectively guard shrimp fromVibrioinvasion. Moreover, shrimps fed with DAO/DEX-CNGs were carefully examined, such as the expression of the immune-related genes, hepatopancreas biopsy, and intestinal microbiota. Few adverse effects on shrimps were observed.ConclusionOur work proposes brand-new applications of multifunctional carbon-based nanomaterials as efficient anti-Vibrioagents in the aquatic industry that hold great potential as feed additives to reduce antibiotic overuse in aquaculture.Graphical Abstract

Pulsed laser irradiation can cause the fragmentation of nanoparticles, which generates cluster ions. This allows nanoparticles to be adopted as mass tag/signal amplifiers in laser desorption/ionization mass spectrometry (LDI-MS) bioassays. Herein, we demonstrate the potential of using the signal from alloy cluster ions in bioassays through a fibrin clot model to determine the activity of thrombin. A mixed solution of silver and gold nanoparticles functionalized with fibrinogen (Fg‒Ag NPs/Fg‒Au NPs) treated with thrombin can form clots composed of aggregated fibrin-Au NPs/Ag NPs. These clots analyzed with LDI-MS are noted to form intense Ag-Au alloy cluster ions, especially [Ag

Bovine serum albumin (BSA)-encapsulated copper sulfide nanocrystals (CuS NCs) were prepared by heating an alkaline solution containing copper ions and BSA without an additional sulfur source. At a high BSA concentration (0.8 mM), nanoassembly of the as-formed CuS NCs occurs to form BSA-CuS NCs as a result of the formation of BSA gel-like structures. In addition to their intrinsic photothermal properties, the BSA-CuS NCs possess rich surface vacancies and thus exhibit enzyme-like and photodynamic activities. Spontaneous generation of hydrogen peroxide (H2O2) led to the in situ formation of copper peroxide (CPO) nanodots on the BSA-CuS NCs to catalyze singlet oxygen radical generation. The antimicrobial response was enhanced by >60-fold upon NIR laser irradiation, which was ascribed to the combined effect of the photodynamic and photothermal inactivation of bacteria. Furthermore, BSA-CuS NCs were transdermally administered onto a methicillin-resistant Staphylococcus aureus-infected wound and eradicated >99% of bacteria in just 1 min under NIR illumination due to the additional peroxidase-like activity of BSA-CuS NCs, transforming H2O2 at the infection site into hydroxyl radicals and thus increasing the synergistic effect from photodynamic and photothermal treatment. The BSA-CuS NCs exhibited insignificant in vitro cytotoxicity and hemolysis and thus can serve as highly biocompatible bactericides in preclinical applications to effectively eradicate bacteria.

In this study, effect of noble metal ions (Au, Ag and Cu) on the synthesis of metal nanoclusters (MNCs) have been investigated. Through heating at 70ºC, TSA/BSA–Au, –Ag and –Cu NCs were separately prepared from Au3+, Ag+ and Cu2+ respectively in the presence of bovine serum albumin (BSA) and thiosalicylic acid (TSA). They exhibit photoluminescence (PL) at 700, 624 and 430 nm, with an average life times of 1500, 100 and 11.71 ns, respectively, when excited at 350 nm. X–ray photoelectron spectroscopy (XPS) data support the presence of metal core (M0) and metal–thiolate shell (Mn–SRm) in each of the TSA/BSA–Metal nanoclusters (MNCs). Spectroscopic measurements reveal the formation of Au32–SR, Ag9–SR and (Cu4–Cu13)–SR species in the TSA/BSA–Au, –Ag and –Cu NCs respectively. Through PL quenching of the TSA/BSA–Au, –Ag and –Cu NCs, they have been used separately for quantitation of Hg2+, As3+ and Cr6+ , with linear ranges of 1400, 418, and 40400 nM and limits of detection (LODs) of 0.25, 2.34 and 3.54 nM, respectively. The PL quenching is mainly due to aggregation of the MNCs via metal–metal or metal–thiol interaction. The stable TSA/BSA–Au, –Ag and –Cu NCs have been employed separately for the determination of the concentrations of Hg2+, As3+ and Cr6+ ions in the spiked sea water samples, showing advantages of simplicity, rapidity, high selectivity, and sensitivity.

Advances in nanoparticle research, particularly in the domain of surface-engineered, function-oriented nanoparticles, have had a profound effect in many areas of scientific research and aided in bringing unprecedented developments forward, particularly in the biomedical field. Surface modifiers/capping agents have a direct bearing on the major properties of metal nanoparticles (MNPs), ranging from their physico-chemical properties to their stability and functional applications. Among the different classes of capping agents, dendrimers have gained traction as effective multifunctional capping agents for MNPs due to their unique structural qualities, dendritic effect and polydentate nature. Dendrimer-coated metal nanoparticles (DC-MNPs) are typically produced by both (i) a one-pot strategy, where metal ions are reduced in the presence of dendrimer molecules and (ii) a multi-pot strategy, where a sequence of reactions involving the reduction of metal ions, activation, conjugation and purification steps are involved. These DC-MNPs have shown remarkable ability to stabilize MNPs by means of electrostatic interactions, coordination chemistry or covalent attachment, due to them entailing a large number of sites at which further molecular moieties can be conjugated. This review article is an attempt to consolidate the on-going work, particularly over the last five years, in the field of the synthesis of dendrimer-coated MNPs and their potential applications in bioimaging, drug delivery and biochemical sensors.

Mercury and its compounds are widely distributed in the environment and have a significant negative impact on human health. In this paper, we report the development of a rapid and facile method for ...

We have prepared copper nanoclusters (Cu NCs) in the presence of bovine serum albumin (BSA) and 1,3-propanedithiol (PDT). The PDT/BSA-Cu NCs possess great activities against different types of bacteria, including non-multidrug-resistant bacteria (Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, and Staphylococcus aureus) and multidrug-resistant bacteria (methicillin-resistant S. aureus). Their minimal inhibitory concentration (MIC) values are at least 242-fold and 10-fold lower than that of the free PDT and BSA-Cu NCs, respectively. The PDT/BSA-Cu NCs are strongly bound to the bacterial membrane, in which they induce the generation of ascorbyl (Asc) and perhydroxyl (HOO) radicals that result in disruption of their membrane integrity. At a concentration of 100-fold higher than their MIC for Escherichia coli, the PDT/BSA-Cu NCs exhibit negligible cytotoxicity towards the tested mammalian cells and show insignificant hemolysis. We have further demonstrated that low-cost PDT/BSA-Cu NCs-coated carbon fiber fabrics (CFFs) are effective against antibacterial growth, showing their great potential for antifouling applications.

In this study, effect of noble metal ion (Au, Ag and Cu) on the synthesis of metal nanoclusters (MNCs) has been investigated. Through heating at 70ºC, TSA/BSA-Au, -Ag and -Cu NCs were separately prepared from Au3+, Ag+, and Cu2+in the presence of bovine serum albumin (BSA) and thiosalicylic acid (TSA). They exhibit photoluminescence (PL) at 700, 624 and 430 nm, with average life times of 1500, 100 and 11.71 ns, respectively, when excited at 350 nm. X–ray photoelectron spectroscopy (XPS) data support the presence of metal core (M0) and metal–thiolate shell (Mn–SRm), each in the TSA/BSA-MNCs. Spectroscopic measurements reveal the formation of Au32–SR, Ag9–SR and (Cu4–Cu13)–SR species separately in the TSA/BSA-Au, -Ag and -Cu NCs. Through PL quenching of the TSA/BSA-Au, -Ag and -Cu NCs, they have been used separately for quantitation of Hg2+, As3+and Cr6+ , with linear ranges of 10-400, 4-18, and 40-400 nM and limits of detection (LODs) of 0.25, 2.34 and 3.54 nM, respectively. The PL quenching is mainly due to aggregation of the MNCs through metallophilic or metal–thiol complexation. The stable TSA/BSA–Au, -Ag and -Cu NCs have been employed separately for the determination of the concentrations of Hg2+, As3+and Cr6+ions in the spiked sea water samples, showing advantages of simplicity, rapidity, high selectivity, and sensitivity.

In this work, we synthesized metal (Au, Ag or Cu)–based nanoclusters (NCs) with different photoluminescence (PL) properties and investigated their application for the specific detection of heavy metal ions in water samples. Bovine serum albumin (BSA) and thiosalicylic acid (TSA) acted as protecting ligands for the synthesis of metallic NCs (MNCs). The as–prepared TSA/BSA–Au NCs, TSA/BSA–Ag NCs and TSA/BSA–Cu NCs exhibit PL emission at 700, 624, and 430 nm, with average lifetimes of 1540, 30.9, and 11.7 ns, respectively, when excited at 350 nm. MNCs has a metal core and metal–thiolate shell, where shell species are Au38–SR24, Ag9–SR7 and Cu3–14–SRm in the TSA/BSA–Au NCs, TSA/BSA–Ag NCs, and TSA/BSA–Cu NCs, respectively. PL quenching of MNCs induced through metallophilic interaction, metal–thiol complexation and/or inner filter effect, which enables the quantitation of Hg2+, As3+, and Cr6+ ions, with linear ranges of 1–350, 1–20, and 50–400 nM, and with limits of detection of 0.25, 0.34 and 3.54 nM, respectively. The TSA/BSA–Au NCs, TSA/BSA–Ag NCs, and TSA/BSA–Cu NCs probe systems exhibit the advantages of simplicity, rapidity, selectivity, sensitivity, and practicality for the quantitation of metal ions in water samples.

In this study, effect of noble metal ion (Au, Ag and Cu) on the synthesis of metal nanoclusters (MNCs) has been investigated. Through heating at 70ºC, TSA/BSA-Au, -Ag and -Cu NCs were separately prepared from Au3+, Ag+and Cu2+in the presence of bovine serum albumin (BSA) and thiosalicylic acid (TSA). They exhibit photoluminescence (PL) at 700, 624 and 430 nm,with average life times of 1500, 100 and 11.71 ns,respectively, when excited at 350 nm. X–ray photoelectronspectroscopy (XPS) data support the presence of metal core (M0) and metal–thiolate shell (Mn–SRm), each in the TSA/BSA-MNCs. Spectroscopic measurements reveal the formation of Au32–SR, Ag9–SR and (Cu4–Cu13)–SR species separately in the TSA/BSA-Au, -Ag and -Cu NCs. Through PL quenching of the TSA/BSA-Au, -Ag and -Cu NCs, they have been used separately for quantitation of Hg2+, As3+and Cr6+ , with linear rangesof 10-400, 4-18, and 40-400 nM and limits of detection (LODs) of 0.25, 2.34 and 3.54 nM, respectively. The PL quenching is mainly due to aggregationof the MNCs through metallophilic or metal–thiol complexation.The stable TSA/BSA–Au, -Ag and -Cu NCs have been employed separately for the determination of the concentrations of Hg2+, As3+and Cr6+ions in the spiked sea water samples, showing advantages of simplicity, rapidity, high selectivity, and sensitivity.

Glucose-capped silver nanoparticles are used as probe for mercury detection. The sensing is based on amalgam formation resulting in decreased absorbance and blue-shift in absorption maxima. The method could selectively sense mercury upto 200 nM.

Energy and efficiency are always the main concern in wireless sensor network. In a sensor network the nodes are present with limited energy and with each transmission they loss some energy. Because of this it is required to minimize the rerouting to save the energy loss. Our work is defined in same area. We proposed an algorithm to get the efficiency as well as the reliability. In this work an energy efficient maximally covered sensor network algorithm is presented such that addresses the requirements of power efficient infrastructure issues for WSN. In this work we proposed a bio inspired dynamic route identification approach in case of any broken link or intrusion in the path. The system will look for the compromising path to optimize the throughput

Mobile ad-hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any stand-alone infrastructure or centralized administration. Mobile ad-hoc network have the attribute such as wireless connection, continuously changing topology, distributed operation and ease of deployment. In this paper we have investigated the performance of two MANET routing protocol (Proactive and Reactive) by using Freeway and Random Waypoint mobility model for mobility of nodes using TCP traffic. Freeway Mobility model has been generated by IMPORTANT (Impact of Mobility Patterns on Routing in Ad-hoc NeTwork) tool, whereas Random Waypoint by inbuilt setdest tool in NS2. A detailed simulation has been carried out in NS2 with TCP traffic sources and AODV as reactive and DSDV as proactive routing protocols. The metrics used for performance analysis are Packet Delivery Fraction, Average end-to-end Delay, Packet Loss, Routing Overhead, Normalized Routing Load and throughput. It has been observed that (proactive routing protocol) DSDV performance is better than (reactive routing protocol) AODV but at the cost of higher average end-end delay in both mobility models. Both routing protocols give optimized result in Random Waypoint mobility model as compared to Freeway Mobility Model.

In this paper, an approach to generate a mechanism for bioinformatics web services to register them with a Data Collaborator Web Service has been presented. The aim of this approach is to create new collaborator service model using existing web services. Up to now, the focus has been on answering specific user queries. On the contrary, the plan is to focus on an automated mechanism that can work as a data collaborator web service. This mechanism would be able to respond to a range of inputs to provide desired and efficient output that are required by the service user.