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ACS Sensors

Fan Feng, Xi Chen, Guojie Li, Song Liang, Zhangyong Hong, He-Fang Wang
Traditional photoluminescence resonance energy transfer (PRET)-based sensors are widely applied, but still suffer from the severe background interference from in situ excitation. The afterglow nature of the persistent luminescence nanoparticles (PLNPs) allows optosensing after the stoppage of in situ illumination, and thus subtly overcomes that interference. We proposed a simple strategy for functionalizing PLNPs for bioanalytical applications and the new afterglow resonance energy transfer (ARET)-based assay for quantitative determination and imaging of fibroblast activation protein-alpha (FAPα) in live cells using Au-decorated Cr3+ 0...
September 18, 2018: ACS Sensors
Nan Hao, Jinwen Lu, Zhou Zhou, Rong Hua, Kun Wang
Colorimetric detection has been widely applied in daily life. However, on the other hand, the further development of colorimetric biosensors has been constrained by the lack of multiple detection capabilities. In this work, we proposed a pH-resolved colorimetric biosensor for the first time for the simultaneous detection of four targets, including ochratoxin A (OTA), aflatoxins B1 (AFB1), fumonisin B1 (FB1) and microcystin-LR (MC-LR). With allochroic dyes as the signal indicators, pH value was introduced as the new dimension to control the release of dyes...
September 17, 2018: ACS Sensors
Jhih-Cheng Wang, Shao-Wen Chi, Tai-Hua Yang, Han-Sheng Chuang
Rapid detection of bacteria and their susceptibility to specific antibiotics plays a vital role in microbial infection treatments. Antimicrobial susceptibility testing (AST) is a common measure to select effective drugs. However, the conventional practices, such as broth dilution, E-test, and disk diffusion, in clinical applications require a long turnaround time (~3 days), thereby compromising treatments and increasing mortality. This study presents self-powered sensors for on-site microorganism monitoring and rapid AST based on functionalized microbeads...
September 17, 2018: ACS Sensors
Bo Tian, Yuanyuan Han, Erik Wetterskog, Marco Donolato, Mikkel Fougt Hansen, Peter Svedlindh, Mattias Strömberg
DNA-assembled nanoparticle superstructures offer numerous bioresponsive properties that can be utilized for point-of-care diagnostics. Functional DNA sequences such as deoxyribozymes (DNAzymes) provide novel bioresponsive strategies and further extend the application of DNA-assembled nanoparticle superstructures. In this work, we describe a microRNA detection biosensor that combines magnetic nanoparticle (MNP) assemblies with DNAzyme-assisted target recycling. The DNA scaffolds of the MNP assemblies contain substrate sequences for DNAzyme and can form cleavage catalytic structures in the presence of target DNA or RNA sequences, leading to rupture of the scaffolds and disintegration of the MNP assemblies...
September 17, 2018: ACS Sensors
Boqun Liu, Sara N Mavrova, Jonas van den Berg, Sebastian K Kristensen, Luca Mantovanelli, Liesbeth M Veenhoff, Bert Poolman, Arnold J Boersma
Förster resonance energy transfer (FRET)-based sensors are a valuable tool to quantify cell biology, yet it remains necessary to identify and prevent potential artifacts in order to exploit their full potential. We show here that artifacts arising from slow donor mCerulean3 maturation can be substantially diminished by constitutive expression in both prokaryotic and eukaryotic cells, which can also be achieved by incorporation of faster-maturing FRET donors. We developed an improved version of the donor mTurquoise2 that matures faster than the parent protein...
September 12, 2018: ACS Sensors
Appu Vengattoor Raghu, Karthikeyan K Karuppanan, Biji Pullithadathil
Herein, we report a facile approach for the synthesis of TiO2 nanoparticles tethered on 2D mixed valent vanadium oxide (VO x /TiO2 ) nanoflakelets using a thermal decomposition assisted hydrothermal method and investigation of its temperature-independent performance enhancement in oxygen-sensing properties. The material was structurally characterized using XRD, TEM, Raman, DSC, and XPS analysis. The presence of mixed valent states, such as V2 O5 and VO2 in VO x , and the metastable properties of VO2 have been found to play crucial roles in the temperature-independent electrical conductivity of VO x /TiO2 nanoflakelets...
September 12, 2018: ACS Sensors
Martin Dulac, Armelle Melet, Erwan Galardon
A new detection system for the endogenous gaseous transmitter and environmental pollutant hydrogen sulfide is presented. It is based on the modulation of the fluorescence spectrum of a coumarin dye by the absorption spectrum of the recombinant hemoglobin I from clam Lucina Pectinata upon coordination of the analyte. While we establish that the reported affinity of rHbI for H2S has been overestimated, the association of the protein with an appropriate fluorophore allows fast, easy and reversible detection and quantification of hydrogen sulfide in buffer as well as biological fluids such as human plasma, with a quantification limit below 100 nM...
September 11, 2018: ACS Sensors
Shi-Yu Liu, Hao Xiong, Jia-Qian Yang, Shu-Hou Yang, Wen-Chao Yang, Guang-Fu Yang
Butyrylcholinesterase (BChE) is widely distributed in various tissues and highly implicated in several important human diseases especially Alzheimer's disease (AD). However, the role of BChE in AD is still controversial, which may be partially attributed to the lack of direct tool for real-time and noninvasive monitoring of BChE in in vivo. Here, we report three rationally designed near-infrared fluorogenic probes that possesses excellent discrimination for butyrylcholinesterase (BChE) over the related enzyme acetylcholinesterase (AChE)...
September 11, 2018: ACS Sensors
Xing Su, Noureddine Tayebi, Grace M Credo, Kai Wu, Oguz H Elibol, David J Liu, Jonathan S Daniels, Handong Li, Drew A Hall, Madoo Varma
Clinical diagnostic assays that monitor redox enzyme activity are widely used in small, low-cost readout devices for point-of-care monitoring (e.g., a glucometer); however, monitoring non-redox enzymes in real-time using compact electronic devices remains a challenge. We address this problem by using a highly scalable nanogap sensor array to observe electrochemical signals generated by a model non-redox enzyme system, the DNA polymerase-catalyzed incorporation of four modified, redox-tagged nucleotides. Using deoxynucleoside triphosphates (dNTPs) tagged with para-aminophenyl monophosphate (pAPP) to form pAP-deoxyribonucleoside tetra-phosphates (AP-dN4Ps), incorporation of the nucleotide analogs by DNA polymerase results in the release of redox inactive pAP-triphosphates (pAPP3 ) that are converted to redox active small molecules para-aminophenol (pAP) in the presence of phosphatase...
September 11, 2018: ACS Sensors
Akihisa Miyagawa, Makoto Harada, Tetsuo Okada
A novel scheme for DNA sensing at the zeptomole level is presented, based on the levitation of a single microsphere in a combined acoustic-gravitational (CAG) field. The levitation of a microsphere in the field is predominantly determined by its density. Capture and reporter probe DNAs are anchored on poly(methyl methacrylate) microsphere (PMMA) and gold nanoparticles (AuNPs), respectively, and a target DNA induces the binding of AuNPs on PMMA. This interparticle sandwich DNA-hybridization induces density increase in PMMA, which is detected as a shift in the levitation coordinate in the CAG field...
September 11, 2018: ACS Sensors
Guoyong Liu, Jiahui Zhao, Shasha Lu, Shuang Wang, Jian Sun, Xiurong Yang
Being a typical copper-containing oxidase, tyrosinase plays critical roles in biological activity, and its aberrant expression might cause diverse skin diseases. Herein, we, for the first time, have found an interesting green fluorogenic reaction between methyldopa and ethanolamine. By combining transmission electron microscopy, UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and MALDI-TOF mass spectrum analysis, we have confirmed that there is a reliable method for preparing the bright green fluorescent polymethyldopa nanoparticles (PMNPs) by simply mixing methyldopa and ethanolamine at room temperature...
September 11, 2018: ACS Sensors
Scott A Walper, Guillermo Lasarte Aragonés, Kim E Sapsford, Carl W Brown, Clare E Rowland, Joyce C Breger, Igor L Medintz
Although a fundamental understanding of the pathogenicity of most biothreat agents has been elucidated and available treatments have increased substantially over the past decades, they still represent a significant public health threat in this age of (bio)terrorism, indiscriminate warfare, pollution, climate change, unchecked population growth, and globalization. The key step to almost all prevention, protection, prophylaxis, post-exposure treatment, and mitigation of any bioagent is early detection. Here, we review available methods for detecting bioagents including pathogenic bacteria and viruses along with their toxins...
September 11, 2018: ACS Sensors
Lei Feng, Yongliang Yang, Xiaokui Huo, Xiangge Tian, Yujie Feng, Hanwen Yuan, Lijian Zhao, Chao Wang, Peng Chu, Feida Long, Wei Wang, Xiaochi Ma
β-Glucuronidase (GLU) as a vital factor in enterohepatic circulation and drug-inducing enteropathy has been given more and more attention in recent years. In this study, an off-on near-infrared (NIR) fluorescent probe (DDAO-glu) for selectively and sensitively sensing GLU was developed on the basis of its substrate preference. DDAO-glu can rapidly and selectively respond to bacterial GLU under physiological conditions for detecting the real-time intestinal GLU bioactivity of complex biological systems such as human feces in clinic...
September 10, 2018: ACS Sensors
Noorhayati Idros, Daping Chu
Heavy metals are highly toxic at trace levels and their pollution has shown great threat to the environment and public health worldwide where current detection methods require expensive instrumentation and laborious operation, which can only be accomplished in centralized laboratories. Herein, we report a low-cost, paper-based microfluidic analytical device (µPAD) for a facile, portable and disposable monitoring of mercury, lead, chromium, nickel, copper and iron ions. Triple indicators or ligands that contain ions or molecules are preloaded on the µPADs and upon addition of a metal ion, the colorimetric indicators will elicit colour changes observed by the naked eyes...
September 7, 2018: ACS Sensors
Soo-Yeon Cho, Hyunah Ahn, Kangho Park, Junghoon Choi, Hohyung Kang, Hee-Tae Jung
Precise control of the size and interfaces of Pd grains is very important for designing a high-performance H2 sensing channel because the transition of the Pd phase from α to β occurs through units of single grains. However, unfortunately, the grain controllability of previous approaches has been limited to grains exceeding 10 nm in size and simple macroscopic channel structures have only shown monotonic response behavior for a wide concentration range of H2. In this work, for the first time, we found that Pd channels that are precisely grain-controlled show very different H2 sensing behavior...
September 7, 2018: ACS Sensors
Gen He, Chengduan Yang, Tian Hang, Di Liu, Hui-Jiuan Chen, Ai-Hua Zhang, Dian Lin, Jiangming Wu, Bo-Ru Yang, Xi Xie
Techniques used to understand the dynamic expression of intracellular proteins are critical in both fundamental biological research and biomedical engineering. Various methods for analyzing proteins have been developed, but these methods require the extraction of intracellular proteins from the cells resulting in cell lysis and subsequent protein purifications from the lysate, which limits the potential of repetitive extraction from the same set of viable cells to track dynamic intracellular protein expression...
September 5, 2018: ACS Sensors
Yuanyuan Sun, Hui Tian, Chenghui Liu, Dandan Yang, Zhengping Li
Precise detection of the low copy numbers of messenger RNA (mRNA) mutation in single cells is of great significance but still remains challenging. Herein, by integrating the outstanding features of a rationally designed peptide nucleic acid (PNA) clamp for highly selective discrimination of single-nucleotide variation, and droplet digital PCR for ultrasensitive and precise quantification, we have developed a robust one-step droplet digital reverse transcription PCR (ddRT-PCR) method which enables precise mRNA mutation detection in single cells with ultrahigh specificity to clearly discern as low as 0...
September 5, 2018: ACS Sensors
Mengdi Hou, Xiyue Liang, Tingting Zhang, Chengyu Qiu, Jingdong Chen, Shaoding Liu, Wenjie Wang, Xudong Fan
We conduct DNA high-resolution melting (HRM) analysis using optofluidic lasers based on a Fabry-Pérot microcavity. Compared to the fluorescence-based HRM, the laser-based HRM has advantages of higher emission intensity for better signal-to-noise ratio and sharper transition for better temperature resolution. In addition, the melting temperature can be lowered by optimizing the laser conditions such as external pump and cavity Q-factor. In this work, we first theoretically analyze the laser-based HRM. Then experiments are performed on three long DNA sequences as model systems, one being 99 bases and the other two being 130 bases long but with different GC contents...
September 5, 2018: ACS Sensors
Antonio Alessio Leonardi, Maria Josè Lo Faro, Salvatore Petralia, Barbara Fazio, Paolo Musumeci, Sabrina Conoci, Alessia Irrera, Francesco Priolo
The realization of an innovative label- and PCR-free silicon nanowires (NWs) optical biosensor for direct genome detection is demonstrated. The system is based on the cooperative hybridization to selectively capture DNA and on the optical emission of quantum confined carriers in Si NWs whose quenching is used as detection mechanism. The Si NWs platform was tested with Hepatitis B virus (HBV) complete genome and it was able to reach a Limit of Detection (LoD) of 2 copies/reaction for the synthetic genome and 20 copies/reaction for the genome extracted from human blood...
September 5, 2018: ACS Sensors
Dong-Il Moon, Beomseok Kim, Ricardo Peterson, Kazimieras Badokas, Myeong-Lok Seol, Debbie G Senesky, Jin-Woo Han, M Meyyappan
Successful transition to commercialization and practical implementation of nanotechnology innovations may very well need device designs that are tolerant to the inherent variations and imperfections in all nanomaterials including carbon nanotubes, graphene, and others. As an example, a single-walled carbon nanotube network based gas sensor is promising for a wide range of applications such as environment, industry, and biomedical and wearable devices due to its high sensitivity, fast response, and low power consumption...
September 4, 2018: ACS Sensors
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