13 research outputs found
Low-cost flexible plasmonic nanobump metasurfaces for label-free sensing of serum tumor marker.
The use of plasmonic metasurface for sensing has great potential on label-free detection of human tumor markers, which could benefit clinical examination. In this work, we adopt nanoimprint and plasma etching to optimize the nanofabrication for low-cost flexible plasmonic metasurface sensors with gold nanobump arrays, which enable facile surface bio-functionality, high sensitivity and simple optical measurement in the visible range. A high bulk refractive index sensitivity of 454.4 nm/RIU is achieved for the prototype plasmonic metasurface sensors at the wavelengths from 620 nm to 720 nm. The rapid quantitative tumor marker sensing of carcinoembryonic antigen in human serum samples from less than 10 ng/mL to more than 87 ng/mL is achieved, which demonstrates good agreement with the conventional chemiluminescence immunoassay system and sufficiently covers the threshold tumor marker concentration of 20 ng/mL for early cancer prediction. Our method is capable of low-cost high-throughput manufacturing for flexible lightweight plasmonic metasurface sensors, which will facilitate wide applications on portable biomedical sensing devices for future point-of-care diagnosis and mobile healthcare
Low-cost flexible plasmonic nanobump metasurfaces for label-free sensing of serum tumor marker
Abstract(#br)The use of plasmonic metasurface for sensing has great potential on label-free detection of human tumor markers, which could benefit clinical examination. In this work, we adopt nanoimprint and plasma etching to optimize the nanofabrication for low-cost flexible plasmonic metasurface sensors with gold nanobump arrays, which enable facile surface bio-functionality, high sensitivity and simple optical measurement in the visible range. A high bulk refractive index sensitivity of 454.4 nm/RIU is achieved for the prototype plasmonic metasurface sensors at the wavelengths from 620 nm to 720 nm. The rapid quantitative tumor marker sensing of carcinoembryonic antigen in human serum samples from less than 10 ng/mL to more than 87 ng/mL is achieved, which demonstrates good agreement with the conventional chemiluminescence immunoassay system and sufficiently covers the threshold tumor marker concentration of 20 ng/mL for early cancer prediction. Our method is capable of low-cost high-throughput manufacturing for flexible lightweight plasmonic metasurface sensors, which will facilitate wide applications on portable biomedical sensing devices for future point-of-care diagnosis and mobile healthcare
Construction of Vibronic Diabatic Hamiltonian for Excited-State Electron and Energy Transfer Processes
Photoinduced excited-state
electron and energy transfer processes
are crucial in biological photoharvesting systems and organic photovoltaic
devices. We discuss the construction of a diabatic vibronic Hamiltonian
for the proper treatment of these processes involving the projection
approach acting on both electronic wave functions and vibrational
modes. In the electronic part, the wave function projection approach
is used to construct the diabatic Hamiltonian in which both local
excited states and charge-transfer states are included on the same
footing. For the vibrational degrees of freedom, the vibronic couplings
in the diabatic Hamiltonian are obtained in the basis of the pseudonormal
modes localized on each monomer site by applying delocalized-to-localized
mode projection. This systematic approach allows us to construct the
vibronic diabatic Hamiltonian in molecular aggregates
Ultrafast Nonadiabatic Dynamics of Singlet Fission: Quantum Dynamics with the Multilayer Multiconfigurational Time-Dependent Hartree (ML-MCTDH) Method
Singlet fission (SF) is supposed
to potentially improve the efficiency
of solar energy conversion in organic photovoltaic systems. The multilayer
multiconfigurational time-dependent Hartree (ML-MCTDH) method was
employed to describe the singlet fission of the pentacene system with
a three-state model. The ML-MCTDH result agrees well with the previous
simulations using the Redfield theory, the hierarchical equation of
motion (HEOM) and the symmetrical quasi-classical (SQC) theory. We
carefully investigated the role of vibrational modes with different
frequencies in singlet fission dynamics. Interestingly, we observed
the important contribution of a few modes with frequency resonance
to electronic transition. Such a finding can be understood by revisiting
the superexchange mechanism within the framework of Fermi’s
golden rule. As a numerically exact method, ML-MCTDH not only provides
an accurate description of the microscopy insight of the SF dynamics
but also provides benchmark results to examine the performance of
other approximated dynamical methods
The Data-Driven Modeling of Pressure Loss in Multi-Batch Refined Oil Pipelines with Drag Reducer Using Long Short-Term Memory (LSTM) Network
Due to the addition of the drag reducer in refined oil pipelines for increasing the pipeline throughput as well as reducing energy consumption, the classical method based on the Darcy-Weisbach Formula for precise pressure loss calculation presents a large error. Additionally, the way to accurately calculate the pressure loss of the refined oil pipeline with the drag reducer is in urgent need. The accurate pressure loss value can be used as the input parameter of pump scheduling or batch scheduling models of refined oil pipelines, which can ensure the safe operation of the pipeline system, achieving the goal of energy-saving and cost reduction. This paper proposes the data-driven modeling of pressure loss for multi-batch refined oil pipelines with the drag reducer in high accuracy. The multi-batch sequential transportation process and the differences in the physical properties between different kinds of refined oil in the pipelines are taken into account. By analyzing the changes of the drag reduction rate over time and the autocorrelation of the pressure loss sequence data, the sequential time effect of the drag reducer on calculating pressure loss is considered and therefore, the long short-term memory (LSTM) network is utilized. The neural network structure with two LSTM layers is designed. Moreover, the input features of the proposed model are naturally inherited from the Darcy-Weisbach Formula and on adaptation to the multi-batch sequential transportation process in refined oil pipelines, using the particle swarm optimization (PSO) algorithm for network hyperparameter tuning. Case studies show that the proposed data-driven model based on the LSTM network is valid and capable of considering the multi-batch sequential transportation process. Furthermore, the proposed model outperforms the models based on the Darcy-Weisbach Formula and multilayer perceptron (MLP) from previous studies in accuracy. The MAPEs of the proposed model of pipelines with the drag reducer are all less than 4.7% and the best performance on the testing data is 1.3627%, which can provide the calculation results of pressure loss in high accuracy. The results also indicate that the model’s capturing sequential effect of the drag reducer from the input data set contributed to improving the calculation accuracy and generalization ability
Ultrafast Excited-State Energy Transfer in DTDCTB Dimers Embedded in a Crystal Environment: Quantum Dynamics with the Multilayer Multiconfigurational Time-Dependent Hartree Method
Photoinduced
excited-state energy transfer (EET) processes play
a key role in the solar energy conversion of small molecule organic
solar cells. We investigated intermolecular EET dynamics in the 2-[[7-(5-<i>N</i>,<i>N</i>-ditolylaminothiophen-2-yl)-2,1,3-benzothiadiazol-4-yl]Âmethylene]Âmalononitrile
(DTDCTB) dimer embedded in a crystal environment using full quantum
dynamics, i.e., the multilayer multiconfigurational time-dependent
Hartree (ML-MCTDH) method. Two different stacking statuses of the
DTDCTB dimers, which occur along the OA axis in the DTDCTB crystal,
were considered. We built a vibronic diabatic Hamiltonian using the
projection method based on quantum mechanics/molecular mechanics results.
Different model Hamiltonians were considered in the full quantum dynamics
studies. First, reduced-dimensional models were constructed by simply
including more of the important vibrational modes. Second, we tried
to construct a continuous spectral density based on the vibronic coupling
strengths of different modes and then created a set of “pseudomodes”
to represent electron–phonon couplings. The dynamics results
based on these reduced models were compared with the results obtained
with the full dimensional model. Our theoretical descriptions demonstrated
that ultrafast intermolecular EET dynamics takes place in the well-stacked
DTDCTB dimers. This work deepens our understanding of the photoinduced
ultrafast EET dynamics of realistic organic photovoltaic systems at
the full quantum mechanical level