Selective detection of an antibiotic using hydrogen-bonded organic frameworks (HOFs): insights from DFT mechanistic analysis.

The development of non-toxic, cost-effective and high fluorescent sensing materials has earned significant interest in the last decade. In this work, a simple synthesis technique of mesoporous hydrogen-bonded organic frameworks (HOFs) suitable for the ultrasensitive detection of a commonly used antibiotic, enrofloxacin (ENR), has been reported. The fluorescence of the HOF is completely quenched after the formation of a HOF-Cu complex as a turn off sensor which undergoes a turn-on mechanism in the presence of ENR.

Cancer Cell Detection and Precision Targeting Drug Delivery by Covalently Functionalized Liposome.

In diagnostics, targeting ability is still a topic of concern for cancer cell detection as well as the drug delivery process. Selective detection of cancer cells from normal cells is a highly demanding but also crucial and challenging task. Recent emergence of folic acid as a targeting ligand can improve the drug delivery systems specifically targeted to cancer cells due to the high affinity to bind the folate receptor (FR) on the surface of cancer cells.

Concurrent targeted delivery of doxorubicin and curcumin to the cancer cells using simple and versatile ligand-installed multifaceted chitosan-based nanoconjugates.

Existing chemotherapeutic approaches against refractory cancers are ineffective due to off-target effects, inefficient delivery, and inadequate accumulation of anticancer drugs at the tumor site, which causes limited efficiency of drug treatment and toxicity to neighboring healthy cells. The development of nano-based drug delivery systems (DDSs) with the goal of delivering desired therapeutic doses to the diseased cells and has already proven to be a promising strategy to address these challenges. Our study focuses on achieving an efficient tumor-targeted delivery of a combination of drugs for therapeutic benefits by developing a versatile DDS by following a simple one-step chemical approach.

Dual-Mode Virus Detection: Combining Electrochemical and Fluorescence Modalities for Enhanced Sensitivity and Reliability.

This study introduces a dual-mode biosensor specifically designed for the quantitative detection of viruses in rapid analysis. The biosensor is unique in its use of both optical (fluorescence) and electrochemical (impedance) detection methods using the same nanocomposites, providing a dual confirmation system for virus (norovirus-like particles) quantification. The system is based on using two antibody-conjugated nanocomposites: CdSeS quantum dots and Au-N,S-GQD nanocomposites.

Point-of-care dengue detection: polydopamine-modified electrode for rapid NS1 protein testing for clinical samples.

Early diagnosis of dengue infection by detecting the dengue virus non-structural protein 1 (DENV-NS1) is important to the patients to initiate speedy treatment. Enzyme-linked immunosorbent assay (ELISA)-based NS1 detection and RT-PCR are time-consuming and too complex to be employed in remote areas of dengue-endemic countries. Meanwhile, those of NS1 rapid test by lateral flow assay suffer from low detection limit.

Development of disposable electrode for the detection of mosquito-borne viruses.

Development of disposable, rapid, and convenient biosensor with high sensitivity and reliability is the most desired method of viral disease prevention. To achieve this goal, in this work, a practical impedimetric biosensor has been implemented into a disposable electrode on a screen-printed carbon electrode (SPCE) for the detection of two mosquito-borne viruses. The biosensor fabrication has step-wisely carried out on the disposable electrode surface at room temperature: starting from conductive film formation, physical binding of the gold nanoparticles (AuNPs)-polyaniline (PAni) into the conductive film, and biofunctionalization.

PSS functionalized and stabilized carbon nanodots for specific sensing of iron in biological medium.

Carbon Quantum Dots (CQDs) are already emerged as an excellent sensing element for its exceptional behavior in fluorescence, biocompatibility, and water dispersibility. However, its poor stability, selectivity and reproducibility in complex medium still be a big problem for its practical application. To overcome this, in the work, we have developed a new type of carbon quantum dot-PSS fluorescent nanocomposites which has been used for specific Fe detection.

Advancement of dengue virus NS1 protein detection by 3D-nanoassembly complex gold nanoparticles utilizing competitive sandwich aptamer on disposable electrode.

Signal amplification have been centralized in developing the highly reliable biosensor for analyte detection with a narrow detection window. We proposed an aptasensor to provide a highly sensitive early-stage diagnostic platform of dengue virus NS1 protein (DENV-NS1) by dual-approach - colorimetric and electrochemical detection. This work utilized two different aptamers specific to DENV-NS1: One conjugated to gold nanoparticles (AuNPs), forming AuNPs-Apt and its complementary sequence aptamer, forming AuNPs-Apt.

Design and Analysis of a Single System of Impedimetric Biosensors for the Detection of Mosquito-Borne Viruses.

The treatment for mosquito-borne viral diseases such as dengue virus (DENV), zika virus (ZIKV), and chikungunya virus (CHIKV) has become difficult due to delayed diagnosis processes. In addition, sharing the same transmission media and similar symptoms at the early stage of infection of these diseases has become more critical for early diagnosis. To overcome this, a common platform that can identify the virus with high sensitivity and selectivity, even for the different serotypes, is in high demand.

Plasmon Nanocomposite-Enhanced Optical and Electrochemical Signals for Sensitive Virus Detection.

The social impact of virus spread is immeasurable. Vaccine prophylaxes take considerable time to develop because clinical trials are required. The best initial response to an emerging virus is establishing a virus detection technology adapted by simply preparing virus-specific antibodies.

Fluorescent and electrochemical dual-mode detection of Chikungunya virus E1 protein using fluorophore-embedded and redox probe-encapsulated liposomes.

The critical goal of sensitive virus detection should apply in the early stage of infection, which may increase the probable survival rate. To achieve the low detection limit for the early stage where a small number of viruses are present in the sample, proper amplified signals from a sensor can make readable and reliable detection. In this work, a new model of fluorescent and electrochemical dual-mode detection system has been developed to detect virus, taking recombinant Chikungunya virus E1 protein (CHIK-VP) as an example.

Electrochemical detection of white spot syndrome virus with a silicone rubber disposable electrode composed of graphene quantum dots and gold nanoparticle-embedded polyaniline nanowires.

Background: With the enormous increment of globalization and global warming, it is expected that the number of newly evolved infectious diseases will continue to increase. To prevent damage due to these infections, the development of a diagnostic method for detecting a virus with high sensitivity in a short time is highly desired. In this study, we have developed a disposable electrode with high-sensitivity and accuracy to evaluate its performances for several target viruses.

Hollow magnetic-fluorescent nanoparticles for dual-modality virus detection.

Combination of magnetic nanomaterials with multifunctionality is an emerging class of materials that exhibit tremendous potential in advanced applications. Synthesizing such novel nanocomposites without compromising magnetic behavior and introducing added functional properties is proven challenging. In this study, an optically active quantum dot (QD) (core) encapsulated inside iron oxide (hollow shell) is prepared as the first electrochemical/fluorescence dual-modality probe.

Controlling distance, size and concentration of nanoconjugates for optimized LSPR based biosensors.

In this report, we have examined the distance- and size-dependent localized surface plasmon resonance (LSPR) between fluorescent quantum dots (QDs) and adjacent gold nanoparticles (AuNPs) to provide a comprehensive evaluation, aiming for practical application in biosensing platform. A series of peptides with different chain lengths, connected between QDs and AuNPs is initially applied to prepare various CdSe QDs-peptide-AuNP systems to optimize LSPR signal. Separation distance between two nanoparticles of these systems before and after conjugation is also confirmed by quantum mechanical modeling and corroborated with their LSPR influenced fluorescence variations.

Ultrasensitive Detection of the Hepatitis E Virus by Electrocatalytic Water Oxidation Using Pt-CoO Hollow Cages.

A sensitive virus detection method applicable for an early stage increases the probability of survival. Here, we develop a simple and rapid detection strategy for the detection of the hepatitis E virus (HEV) by an electrocatalytic water oxidation reaction (WOR) using a platinum (Pt)-incorporated cobalt (Co)-based zeolite imidazole framework (ZIF-67). The surface cavity of ZIF-67 enables the rich loading of Pt NPs, and subsequent calcination etches the cavity, promoting the electrocatalytic activity of Pt-CoO HCs.

Use of Target-Specific Liposome and Magnetic Nanoparticle Conjugation for the Amplified Detection of Norovirus.

Viral diseases are one of the most life-threatening diseases as they can erupt unpredictably and spread rapidly in any medium with a very small number of particles. Therefore, the key for lethal virus detection should be highly sensitive in the early-stage detection, which can help increase the chance of survival. Amplification of the detecting signal is one of the most promising mechanisms for the detection of low-concentration analytes.

Advancement of capture immunoassay for real-time monitoring of hepatitis E virus-infected monkey.

Rapid increasing outbreak of Hepatitis E virus (HEV) shows an urgent need of HEV detection. Instead of time consuming and expensive RT-qPCR, an efficient and quick monitoring system is in utmost demand which can be comparable with the RT-qPCR in term of reliability and detection limit. An advanced platform for immunoassay has been constructed in this study by a nanozyme that constitutes anti-HEV IgG antibody-conjugated gold nanoparticles (Ab-AuNPs) as core and in situ silver deposition on the surface of Ab-AuNPs as outer shell.

Fluorometric virus detection platform using quantum dots-gold nanocomposites optimizing the linker length variation.

In this study, a tunable biosensor using the localized surface plasmon resonance (LSPR), controlling the distance between fluorescent CdZnSeS/ZnSeS quantum dots (QDs) and gold nanoparticles (AuNPs) has been developed for the detection of virus. The distance between the AuNPs and QDs has been controlled by a linkage with a peptide chain of 18 amino acids. In the optimized condition, the fluorescent properties of the QDs have been enhanced due to the surface plasmon effect of the adjacent AuNPs.

Dual modality sensor using liposome-based signal amplification technique for ultrasensitive norovirus detection.

Sensitive and accurate detection methods for infectious viruses are the pressing need for effective disease diagnosis and treatment. Herein, based on VO nanoparticles-encapsulated liposomes (VONP-LPs) we demonstrate a dual-modality sensing platform for ultrasensitive detection of the virus. The sensing performance relies on intrinsic peroxidase and electrochemical redox property of VO nanoparticles (VO NPs).

The detection and identification of dengue virus serotypes with quantum dot and AuNP regulated localized surface plasmon resonance.

The dengue hemorrhagic fever or dengue shock syndrome has become a severe human fatal disease caused by infection with one of the four closely related but serologically distinct dengue viruses (DENVs). All four dengue serotypes are currently co-circulating throughout the subtropics and tropics. Since the fatality rate increases severely when a secondary infection occurs by a virus serotype different from that of the initial infection, serotype identification is equally important as virus detection.

Electrical pulse-induced electrochemical biosensor for hepatitis E virus detection.

Hepatitis E virus (HEV) is one of the leading causes of acute viral hepatitis worldwide. In this work, a pulse-triggered ultrasensitive electrochemical sensor was fabricated using graphene quantum dots and gold-embedded polyaniline nanowires, prepared via an interfacial polymerization and then self-assembly approach. Introducing an external electrical pulse during the virus accumulation step increases the sensitivity towards HEV due to the expanded surface of the virus particle as well as the antibody-conjugated polyaniline chain length, compared to other conventional electrochemical sensors.

Femtomolar Detection of Dengue Virus DNA with Serotype Identification Ability.

Dengue surveillance trusts only on reverse transcription-polymerase chain reaction (RT-PCR) type methodologies for confirmation of dengue virus serotypes; however, its real time application is restricted due to the expensive, complicated, and time-consuming process. In search of a new sensing system, here, we have reported a two-way-detection method for Dengue virus (DENV) serotype identification along with DNA quantification by using a new class of nanocomposite of gold nanoparticles (AuNP) and nitrogen, sulfur codoped graphene quantum dots (N,S-GQDs). The N,S-GQDs@AuNP has been used for serotype detection via a simple fluorescence technique using four dye-combined probe DNAs which is further validated by confocal microscopy.

Impedimetric biosensor for detection of cancer cells employing carbohydrate targeting ability of Concanavalin A.

The successful development of selective detection of cancer cells from normal cells is a highly demanded but challenging task. Herein, we have developed a rapid and label-free impedimetric biosensor for quantitative determination of cancer cells with high glycoprotein expression. Homogenously distributed 2-9 nm graphene quantum dots (GQDs) was anchored on the surface FeO through covalent bonding.

Single-step detection of norovirus tuning localized surface plasmon resonance-induced optical signal between gold nanoparticles and quantum dots.

A new method of label free sensing approach with superior selectivity and sensitivity towards virlabel-freeon is presented here, employing the localized surface plasmon resonance (LSPR) behavior of gold nanoparticles (AuNPs) and fluorescent CdSeTeS quantum dots (QDs). Inorganic quaternary alloyed CdSeTeS QDs were capped with -cysteine via a ligand exchange reaction. Alternatively, citrate stabilized AuNPs were functionalized with 11-mercaptoundecanoic acid to generate carboxylic group on the gold surface.