scholarly journals Monolithic integration of nanorod arrays on microfluidic chips for fast and sensitive one-step immunoassays

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ye Wang ◽  
Jiongdong Zhao ◽  
Yu Zhu ◽  
Shurong Dong ◽  
Yang Liu ◽  
...  
Keyword(s):  
Troponin I ◽  
Specific Antigen ◽  
Monolithic Integration ◽  
Detection Sensitivity ◽  
Quantitative Detection ◽  
Plasmonic Nanostructures ◽  
Nanorod Arrays ◽  
Microfluidic Chips ◽  
One Step ◽  
Flow Through

AbstractHere, we present integrated nanorod arrays on microfluidic chips for fast and sensitive flow-through immunoassays of physiologically relevant macromolecules. Dense arrays of Au nanorods are easily fabricated through one-step oblique angle deposition, which eliminates the requirement of advanced lithography methods. We report the utility of this plasmonic structure to improve the detection limit of the cardiac troponin I (cTnI) assay by over 6 × 105-fold, reaching down to 33.9 fg mL−1 (~1.4 fM), compared with an identical assay on glass substrates. Through monolithic integration with microfluidic elements, the device enables a flow-through assay for quantitative detection of cTnI in the serum with a detection sensitivity of 6.9 pg mL−1 (~0.3 pM) in <6 min, which was 4000 times lower than conventional glass devices. This ultrasensitive detection arises from the large surface area for antibody conjugation and metal-enhanced fluorescent signals through plasmonic nanostructures. Moreover, due to the parallel arrangement of flow paths, simultaneous detection of multiple cancer biomarkers, including prostate-specific antigen and carcinoembryonic antigen, has been fulfilled with increased signal-to-background ratios. Given the high performance of this assay, together with its simple fabrication process that is compatible with standard mass manufacturing techniques, we expect that the prepared integrated nanorod device can bring on-site point-of-care diagnosis closer to reality.

scholarly journals Detector-Free Photothermal Bar-Chart Microfluidic Chips (PT-Chips) for Visual Quantitative Detection of Biomarkers

2021 ◽  
Author(s):  
Wan Zhou ◽  
Guanglei Fu [email protected] ◽  
Xiujun Li
Keyword(s):  
Whole Blood ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Clinical Diagnostics ◽  
Detection Sensitivity ◽  
Quantitative Detection ◽  
Microfluidic Chips ◽  
Analytical Instruments ◽  
Photothermal Effects ◽  
On Chip

<p>The volumetric bar-chart microfluidic chips (V-Chips) driven by chemical reaction-generated gas provide a promising platform for point-of-care (POC) visual biomarker quantitation. However, multiple limitations are encountered in conventional V-Chips, such as costly and complex chip fabrication, complicated assembly, and imprecise controllability of gas production. Herein, we introduced nanomaterial-mediated photothermal effects to V-Chips, and for the first time developed a new type of V-Chip, <u>p</u>hoto<u>t</u>hermal bar-chart microfluidic <u>c</u>hip (PT-Chip), for visual quantitative detection of biochemicals without any bulky and costly analytical instruments. Immunosensing signals were converted to visual readout signals via photothermal effects, the on-chip bar-chart movements, enabling quantitative biomarker detection on a low-cost polymer hybrid PT-Chip with on-chip scale rulers. Four different human serum samples containing prostate-specific antigen (PSA) as a model analyte were detected simultaneously using the PT-Chip, with the limit of detection of 2.1 ng/mL, meeting clinical diagnostic requirements. Although no conventional signal detectors were used, it achieved comparable detection sensitivity to absorbance measurements with a microplate reader. The PT-Chip was further validated by testing human whole blood without the color interference problem, demonstrating good analytical performance of our method even in complex matrixes and thus the potential to fill a gap in current clinical diagnostics that is incapable of testing whole blood. This new PT-Chip driven by nanomaterial-mediated photothermal effects opens a new horizon of microfluidic platforms for instrument-free diagnostics at the point of care.</p>

scholarly journals Detector-Free Photothermal Bar-Chart Microfluidic Chips (PT-Chips) for Visual Quantitative Detection of Biomarkers

2021 ◽  
Author(s):  
Wan Zhou ◽  
Guanglei Fu [email protected] ◽  
Xiujun Li
Keyword(s):  
Whole Blood ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Clinical Diagnostics ◽  
Detection Sensitivity ◽  
Quantitative Detection ◽  
Microfluidic Chips ◽  
Analytical Instruments ◽  
Photothermal Effects ◽  
On Chip

<p>The volumetric bar-chart microfluidic chips (V-Chips) driven by chemical reaction-generated gas provide a promising platform for point-of-care (POC) visual biomarker quantitation. However, multiple limitations are encountered in conventional V-Chips, such as costly and complex chip fabrication, complicated assembly, and imprecise controllability of gas production. Herein, we introduced nanomaterial-mediated photothermal effects to V-Chips, and for the first time developed a new type of V-Chip, <u>p</u>hoto<u>t</u>hermal bar-chart microfluidic <u>c</u>hip (PT-Chip), for visual quantitative detection of biochemicals without any bulky and costly analytical instruments. Immunosensing signals were converted to visual readout signals via photothermal effects, the on-chip bar-chart movements, enabling quantitative biomarker detection on a low-cost polymer hybrid PT-Chip with on-chip scale rulers. Four different human serum samples containing prostate-specific antigen (PSA) as a model analyte were detected simultaneously using the PT-Chip, with the limit of detection of 2.1 ng/mL, meeting clinical diagnostic requirements. Although no conventional signal detectors were used, it achieved comparable detection sensitivity to absorbance measurements with a microplate reader. The PT-Chip was further validated by testing human whole blood without the color interference problem, demonstrating good analytical performance of our method even in complex matrixes and thus the potential to fill a gap in current clinical diagnostics that is incapable of testing whole blood. This new PT-Chip driven by nanomaterial-mediated photothermal effects opens a new horizon of microfluidic platforms for instrument-free diagnostics at the point of care.</p>

The growth and assembly of the multidimensional hierarchical Ni3S2 for aqueous asymmetric supercapacitors

CrystEngComm ◽  
2015 ◽  
Vol 17 (24) ◽  
pp. 4495-4501 ◽  
Author(s):  
Bin Yang ◽  
Lei Yu ◽  
Qi Liu ◽  
Jingyuan Liu ◽  
Wanlu Yang ◽  
...  
Keyword(s):  
Thin Film ◽  
Energy Storage ◽  
High Performance ◽  
Electrode Materials ◽  
Hydrothermal Process ◽  
Nanorod Arrays ◽  
Asymmetric Supercapacitors ◽  
One Step ◽  
Step Growth

We synthesized the mushroom-like Ni3S2 with step by step growth that is the thin film growing on the nanorod arrays with one-step hydrothermal process, which is a novel ways to fabricate the multidimensional hierarchical electrode materials for high performance energy storage.

scholarly journals Fluorescence Based on Surface Plasmon Coupled Emission for Ultrahigh Sensitivity Immunoassay of Cardiac Troponin I

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 448
Author(s):  
Vien Thi Tran ◽  
Heongkyu Ju
Keyword(s):  
Surface Plasmon ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Limit Of Detection ◽  
Delayed Diagnosis ◽  
Cardiac Troponin I ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Label Free ◽  
Ultrahigh Sensitivity

This work demonstrates the quantitative assay of cardiac Troponin I (cTnI), one of the key biomarkers for acute cardiovascular diseases (the leading cause of death worldwide) using the fluorescence-based sandwich immune reaction. Surface plasmon coupled emission (SPCE) produced by non-radiative coupling of dye molecules with surface plasmons being excitable via the reverse Kretschmann format is exploited for fluorescence-based sandwich immunoassay for quantitative detection of cTnI. The SPCE fluorescence chip utilizes the gold (2 nm)-silver (50 nm) bimetallic thin film, with which molecules of the dye Alexa 488 (conjugated with detection antibodies) make a near field coupling with the plasmonic film for SPCE. The experimental results find that the SPCE greatly improves the sensitivity via enhancing the fluorescence signal (up to 50-fold) while suppressing the photo-bleaching, permitting markedly enhanced signal-to-noise ratio. The limit of detection of 21.2 ag mL−1 (atto-gram mL−1) is obtained, the lowest ever reported to date amid those achieved by optical technologies such as luminescence and label-free optical sensing techniques. The features discovered such as ultrahigh sensitivity may prompt the presented technologies to be applied for early diagnosis of cTnI in blood, particularly for emergency medical centers overloaded with patients with acute myocardial infarction who would suffer from time-delayed diagnosis due to insufficient assay device sensitivity.

Rapid and quantitative detection of mumps virus RNA by one-step real-time RT-PCR

2004 ◽  
Vol 49 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Ayhan Kubar ◽  
Mehmet Yapar ◽  
Bulent Besirbellioglu ◽  
I.Yasar Avci ◽  
Cakır Guney
Keyword(s):  
Real Time ◽  
Mumps Virus ◽  
Quantitative Detection ◽  
Rt Pcr ◽  
Virus Rna ◽  
One Step

scholarly journals Analysis of Urinary Prostate-Specific Antigen Glycoforms in Samples of Prostate Cancer and Benign Prostate Hyperplasia

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Chun-Jen Hsiao ◽  
Tzong-Shin Tzai ◽  
Chein-Hung Chen ◽  
Wen-Horng Yang ◽  
Chung-Hsuan Chen
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Benign Prostate Hyperplasia ◽  
Clinical Sample ◽  
Specific Antigen ◽  
Ion Accumulation ◽  
Detection Sensitivity ◽  
Prostate Hyperplasia ◽  
Liquid Chromatography Tandem Mass ◽  
Benign Prostate

Glycans of prostate-specific antigen (PSA) in prostate cancer were found to be different from that in benign disease. It is difficult to analyze heterogeneous PSA glycoforms in each individual specimen because of low protein abundance and the limitation of detection sensitivity. We developed a method for prostate cancer diagnosis based on PSA glycoforms. Specific glycoforms were screened in each clinical sample based on liquid chromatography-tandem mass spectrometry with ion accumulation. To look for potential biomarkers, normalized abundance of each glycoform in benign prostate hyperplasia (BPH) and in prostate cancer was evaluated. The PSA glycoform, Hex5HexNAc4NeuAc1dHex1, and monosialylated, sialylated, and unfucosylated glycoforms differed significantly between the prostate cancer and BPH samples. The detection sensitivity (87.5%) and specificity (60%) for prostate cancer identification are higher than those of the serum PSA marker. As low as 100 amol PSA could be detected with the ion accumulation method which has not been reported before. The improved detection specificity can help reduce unnecessary examinations.

scholarly journals Insight into the working wavelength of hotspot effects generated by popular nanostructures

2019 ◽  
Vol 8 (1) ◽  
pp. 24-34 ◽  
Author(s):  
Zhong Wang ◽  
Kesu Cai ◽  
Yang Lu ◽  
Haining Wu ◽  
Yuee Li ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Enhancement ◽  
Quantitative Detection ◽  
Excitation Wavelength ◽  
Sers Substrate ◽  
Nanorod Arrays ◽  
Electric Field Enhancement ◽  
Incident Laser ◽  
Incident Wavelength ◽  
Excitation Laser

Abstract A proper excitation wavelength is much important for the application of surface-enhanced Raman spectroscopy (SERS) in the biochemical field. Here, based on a SERS substrate model with an incident Gaussian beam, we investigate the dependence of the electric field enhancement on the incident wavelength of the excitation laser for popular nanostructures, including nanosphere dimer, nanorod dimer, and nanorod arrays. The results in the present manuscript indicate that both the nanosphere and nanorod dimer present a much broader plasmonic excitation wavelength range extending to the near-infrared region. The enhancement effect of Nanorod arrays is strongly dependent on the incident direction of excitation light. Finally, according to the conclusions above, a SERS substrate consisting of nanocubes based on the SPP eigen-mode is proposed and the electric field enhancement is homogeneous, and insensitive to the polarization of the incident laser. The enhancement factor is not ultrahigh; however, good homogeneousness permits for quantitative detection of lower concentration components in mixtures. Graphical abstract: By investigating the dependence of the electric field enhancement on the incident wavelength of the excitation laser for popular nanostructures, we propose a SERS substrate consisting of Au nanocubes based on the SPP eigenmode. The electric field enhancement is homogeneous, and insensitive to the polarization of the incident laser. Though the enhancement factor is not ultrahigh, good homogeneousness permits for quantitative detection of lower concentration components in mixtures.

Sign in / Sign up

Export Citation Format

Share Document