Coauthored Publications with: Lin

Journal Article

Chang, C-L, Tsai P-Y, Chang Y-P, Lin K-C.  2012.  Interfacial electron transfer from CdSe/ZnS quantum dots to TiO 2 nanoparticles: Size dependence at the single-molecule level. ChemPhysChem. 13:2711-2720., Number 11 AbstractWebsite

Electron transfer (ET) kinetics of CdSe/ZnS core/shell quantum dots (QDs) on bare coverslips and a TiO 2 nanoparticle-coated thin film has been investigated at the single-molecule level. The QDs prepared have three different diameters of 3.6, 4.6, and 6.4 nm. The trajectories of fluorescence intensity are acquired with respect to the arrival time. The on-time events and subsequent fluorescence lifetimes are shorter with decreasing size. Given the lifetime measurements for QDs on glass and TiO 2, the rate constant of ET from QDs to TiO 2 may be determined to be 1.3×10 7, 6.0×10 6, and 4.7×10 6 s -1 for the increasing sizes of the QDs. The plot of on-time probability density versus arrival time is characterized by power-law statistics in the short time region and a bending tail in the long time region. Marcus's ET model is employed to satisfactorily fit the bending tail behavior and to further calculate the ET rate constants. The theoretical counterparts for the different sizes are 1.4×10 7, 6.4×10 6, and 1.9×10 6 s -1, showing good agreement with the experimental results. Going dotty: Electron transfer kinetics of CdSe/ZnS core/shell quantum dots (QDs) on bare coverslips and on TiO 2 nanoparticle coated thin films have been investigated at the single-molecule level. As the size of the QDs changes, the shift in the valence band (VB) energy is less significant than the shift in the conduction band (CB) energy. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Tsai, P-Y, Che D-C, Nakamura M, Lin K-C, Kasai T.  2010.  Orientation dependence in the four-atom reaction of OH + HBr using the single-state oriented OH radical beam. Physical Chemistry Chemical Physics. 12:2532-2534., Number 11 AbstractWebsite

The orientation dependence for the Br atom formation in the reaction of the oriented OH radicals with HBr molecules at 0.26 eV collision energy has been observed for the first time using the hexapole electric field, and we found that the reaction cross-section for O-end attack is more favorable than that for H-end attack by a factor of 3.4 ± 2.3. © the Owner Societies.
Lin, C.-H., WCLLKCSMSML-XK-.  2020.  Non-invasive and time-dependent blood-sugar monitoring via breath-derived CO2 correlation using gas chromatograph with a milli-whistle gas analyze. AbstractWebsite

A clear and positive correlation between the CO2 concentration and the blood-sugar level has been observed via a noninvasive and time-dependent monitoring of CO2 concentration from human breath, which is carried out by using a homemade gas chromatography (GC)/milli-whistle compact analyzer. The time-dependent sampling of the CO2 concentration correlated between 5.0 to 5.6% (1% = 104 ppm) in accordance with blood-sugar level variations of 80 to 110 mg/dL. The analytical method results in a rapid, continuous and non-invasive determination of blood-sugar level via measurement of the CO2 concentration exhaled from the lungs.
Dhenadhayalan, N, Lin K-C, Suresh R, Ramamurthy P.  2016.  Unravelling the Multiple Emissive States in Citric-Acid-Derived Carbon Dots. Journal of Physical Chemistry C. 120:1252-1261., Number 2 AbstractWebsite

Steady-state and time-resolved fluorescence spectroscopy techniques were used to probe multifluorescence resulting from citric-acid-derived carbon dots (C-dots). Commonly, both carboxyl-/amine-functionalized C-dots exhibit three distinct emissive states corresponding to the carbon-core and surface domain. The shorter-wavelength fluorescence (below 400 nm) originates from the carbon-core absorption band at ∼290 nm, whereas the fluorescence (above 400 nm) is caused by two surface states at ∼350 and 385 nm. In addition to three emissive states, a molecular state was also found in amine-functionalized C-dots. Time-resolved emission spectra (TRES) and time-resolved area normalized emission spectra (TRANES) were analyzed to confirm the origin of excitation wavelength-dependent fluorescence of C-dots. The surface functional groups on the C-dots are capable of regulating the electron transfer to affect the multifluorescence behavior. The electron transfer takes place from the carbon-core to surface domain by the presence of -COOH on the surface and vice versa for the case of -NH2 present on the surface. To the best of our knowledge, this is the first report that the multiemissive states are probed in C-dots systems using TRES and TRANES analyses, and related fluorescence mechanisms are verified clearly. © 2015 American Chemical Society.
Tsai, P-Y, Hung K-C, Li H-K, Lin K-C.  2014.  Photodissociation of propionaldehyde at 248 nm: Roaming pathway as an increasingly important role in large aliphatic aldehydes. Journal of Physical Chemistry Letters. 5:190-195., Number 1 AbstractWebsite

Time-resolved Fourier transform infrared emission spectroscopy is employed in the photolysis of propionaldehyde (CH3CH2CHO) at 248 nm to characterize the role of the roaming pathway. High-resolution spectra of CO are analyzed to yield a single Boltzmann rotational distribution for each vibrational level (ν = 1-4) with small rotational and large vibrational energy disposals. A roaming saddle point is found containing two far separated moieties of HCO and CH3CH2 with a weak interaction between them. Quasiclassical trajectory calculations on this configuration yield the CO energy flow behavior, consistent with the findings. The rate constant along the roaming pathway is evaluated to be larger by >1-2 orders of magnitude than those along tight transition state or three-body dissociation pathways. This work implies that the roaming mechanism plays an increasingly important role in aliphatic aldehydes as the molecular size becomes larger. © 2013 American Chemical Society.
Wu, C-C, Lin H-C, Chang Y-B, Tsai P-Y, Yeh Y-Y, Fan H, Lin K-C, Francisco JS.  2011.  Br 2 molecular elimination in photolysis of (COBr) 2 at 248 nm by using cavity ring-down absorption spectroscopy: A photodissociation channel being ignored. Journal of Chemical Physics. 135, Number 23 AbstractWebsite

A primary dissociation channel of Br 2 elimination is detected following a single-photon absorption of (COBr) 2 at 248 nm by using cavity ring-down absorption spectroscopy. The technique contains two laser beams propagating in a perpendicular configuration. The tunable laser beam along the axis of the ring-down cell probes the Br 2 fragment in the B 3Π + ou-X 1Σ g + transition. The measurements of laser energy- and pressure-dependence and addition of a Br scavenger are further carried out to rule out the probability of Br 2 contribution from a secondary reaction. By means of spectral simulation, the ratio of nascent vibrational population for v = 0, 1, and 2 levels is evaluated to be 1:(0.65 ± 0.09):(0.34 ± 0.07), corresponding to a Boltzmann vibrational temperature of 893 ± 31 K. The quantum yield of the ground state Br 2 elimination reaction is determined to be 0.11 ± 0.06. With the aid of ab initio potential energy calculations, the pathway of molecular elimination is proposed on the energetic ground state (COBr) 2 via internal conversion. A four-center dissociation mechanism is followed synchronously or sequentially yielding three fragments of Br 2 + 2CO. The resulting Br 2 is anticipated to be vibrationally hot. The measurement of a positive temperature effect supports the proposed mechanism. © 2011 American Institute of Physics.
Nakamura, M, Palazzetti F, Tsai P-Y, Lin K-C, Kasai T, Che D-C, Lombardi A, Aquilanti V.  2019.  Vectorial imaging of the photodissociation of 2-bromobutane oriented: Via hexapolar state selection. Physical Chemistry Chemical Physics. 21(26):14164-14172. AbstractWebsite

Molecular orientation techniques are becoming available in the study of elementary chemical processes, in order to highlight those structural and dynamical properties that would be concealed by random rotational motions. Recently successful orientation was achieved for asymmetric-top and chiral molecules of much larger complexity than hitherto. In this work, we report and discuss the correlation between the vectors' photofragment recoil velocity v, transition dipole moment μ, and permanent dipole moment d in a dissociation experiment on hexapole oriented 2-bromobutane, photoinitiated by a linearly polarized laser. The sliced ion images of the Br∗(2P1/2) and Br(2P3/2) photofragments were acquired at 234.0 and 254.1 nm, respectively, by a (2 + 1) resonance-enhanced multiphoton ionization technique. A detailed analysis of the sliced ion images obtained at a tilting angle 45° of laser polarization provides information on the correlation of the three vectors, which are confined by two polar angles α and χ and one azimuthal angle φμd in the recoil frame. The sliced ion images of Br fragments eliminated individually from the enantiomers at 254.1 nm yield an asymmetric factor close to zero; for this reason the photofragment angular distributions do not show significant differences. The elimination of the Br∗ fragment at 234.0 nm is mainly correlated with a parallel transition, giving rise to a large anisotropy parameter of 1.85, and thus can be considered as a single state excitation. The resulting recoil frame angles are optimized to 163° ± 8° and 164° ± 1° for α and χ, respectively, whereas φμd is approaching 0° for the best fit. Since for the present molecule, the three vectors have an only slight spatial arrangement, the photofragment angular distributions of the two enantiomers do not show appreciable differences. Theoretical and computational simulations provide us the basis to state that oriented enantiomers can be discriminated on-the-fly in photodissociation processes even initiated by non-circularly polarized light, provided that the three vectors encountered above have specific three-dimensional arrangements. The fact that Br fragment elimination involves a multi-potential dissociation carries uncertainties in theoretical estimates of the vector direction. Therefore, this work represents a preliminary but significant step on the road to chiral discrimination on-the-fly, which is shown to be best propitiated in molecules where vectors are far from having degenerate mutual angular directions. © 2019 the Owner Societies.
Veerakumar, P, Thanasekaran P, Lin K-C, Liu S-B.  2017.  Biomass Derived Sheet-like Carbon/Palladium Nanocomposite: An Excellent Opportunity for Reduction of Toxic Hexavalent Chromium. ACS Sustainable Chemistry and Engineering. 5:5302-5312., Number 6 AbstractWebsite

Palladium nanoparticles (Pd NPs) immobilized on a garlic skin-derived activated carbons (GACs) is reported. The morphology, structure, surface compositions, and textural properties of the GACs and Pd@GAC catalyst were investigated by a variety of physicochemical characterization techniques, which revealed a dispersion of Pd NPs with average particle size of ca. 21 nm on sheet-like graphitized GACs with surface areas and pore volumes as high as 1836 m2 g-1 and 0.89 cm3 g-1, respectively. As a result, the Pd@GAC with a Pd loading of ca. 1-2 wt% exhibited superior activity for catalytic reduction of toxic Cr(VI) to Cr(III) surpassing most metal-based catalysts reported in the literature. As evidenced by a comprehensive UV-vis spectrophotometric study, the eco-friendly Pd@GAC catalyst reported herein, which can be facilely prepared with biowaste feedstocks, also showed excellent catalytic performances for efficient reduction of Cr(VI) with extraordinary stability and recyclability over at least five repeated catalytic test cycles. © 2017 American Chemical Society.
Dhenadhayalan, N, Lin K-C.  2015.  Chemically Induced Fluorescence Switching of Carbon-Dots and Its Multiple Logic Gate Implementation. Scientific Reports. 5 AbstractWebsite

Investigations were carried out on the carbon-dots (C-dots) based fluorescent off - on (Fe 3 €‰+ €‰ - S 2 O 3 2 ') and on - off (Zn 2 €‰+ €‰ - PO 4 3 ') sensors for the detection of metal ions and anions. The sensor system exhibits excellent selectivity and sensitivity towards the detection of biologically important Fe 3 €‰+ €‰, Zn 2 €‰+ €‰ metal ions and S 2 O 3 2 ', PO 4 3 ' anions. It was found that the functional group on the C-dots surface plays crucial role in metal ions and anions detection. Inspired by the sensing results, we demonstrate C-dots based molecular logic gates operation using metal ions and anions as the chemical input. Herein, YES, NOT, OR, XOR and IMPLICATION (IMP) logic gates were constructed based on the selection of metal ions and anions as inputs. This carbon-dots sensor can be utilized as various logic gates at the molecular level and it will show better applicability for the next generation of molecular logic gates. Their promising properties of C-dots may open up a new paradigm for establishing the chemical logic gates via fluorescent chemosensors.
Chao, M-S, Tornero J, Lin KC, Stolte S, González Ureña A.  2013.  Decoherence cross-section in NO + Ar collisions: Experimental results and a simple model. Journal of Physical Chemistry A. 117:8119-8125., Number 34 AbstractWebsite

Quantum decoherence can be viewed as the mechanism responsible for the quantum-to-classical transition as the initially prepared quantum state interacts with its environment in an irreversible manner. One of the most common mechanisms responsible for the macroscopically observed decoherence involves collisions of an atom or molecule, initially prepared in a coherent superposition of states, with gas particles. In this work, a coherent superposition of quantum internal states of NO molecules is prepared by the interaction between the molecule with both a static and a radiofrequency electric field. Subsequently, NO + Ar collision decoherence experiments are investigated by measuring the loss of coherence as a function of the number of collisions. Data analysis using a model based on the interaction potential of the collisional partners allowed to unravel the molecular mechanism responsible for the loss of coherence in the prepared NO quantum superposition of internal states. The relevance of the present work relies on several aspects. On the one hand, the use of radio-waves introduces a new way for the production of coherent beams. On the other hand, the employed methodology could be useful in investigating the Stereodynamics of chemical reactions with coherent reagents. © 2013 American Chemical Society.
Chen, S-Y, Tsai P-Y, Lin H-C, Wu C-C, Lin K-C, Sun BJ, Chang AHH.  2011.  I2 molecular elimination in single-photon dissociation of CH2I2 at 248 nm by using cavity ring-down absorption spectroscopy. Journal of Chemical Physics. 134, Number 3 AbstractWebsite

Following single-photon dissociation of CH2I2 at 248 nm, I2 molecular elimination is detected by using cavity ring-down absorption spectroscopy. The technique comprises two laser beams propagating in a perpendicular configuration, in which a tunable laser beam along the axis of the ring-down cell probes the I2 fragment in the B 3 ou + - X 1 g + transition. The nascent vibrational populations for v 0, 1, and 2 levels are obtained with a population ratio of 1:(0.65 0.10):(0.30 0.05), corresponding to a Boltzmann-like vibrational temperature of 544 73 K. The quantum yield of the ground state I2 elimination reaction is determined to be 0.0040 0.0025. With the aid of ab initio potential energy calculations, the pathway of molecular elimination is proposed on the energetic ground state CH2I2 via internal conversion, followed by asynchronous three-center dissociation. A positive temperature effect supports the proposed mechanism. © 2011 American Institute of Physics.
Srinivasan, V, Jhonsi MA, Lin K-C, Ananth DA, Sivasudha T, Narayanaswamy R, Kathiravan A.  2019.  Pyrene-based prospective biomaterial: In vitro bioimaging, protein binding studies and detection of bilirubin and Fe3+. Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy. 211 AbstractWebsite

Herein, we have meticulously derived the nanosized fluorescent aggregates from pyrene Schiff base (PS) in DMSO:water (10:90) ratio. The aggregation property of PS molecule was characterized by SEM and TEM measurements, revealed the aggregated particles are in spherical shape with ~3 nm in size. Moreover, aggregates exhibit a high fluorescence quantum yield (48%) which was effectively used for the in vitro bioimaging of two different cancer cells such as A549 and MCF-7 cells in which it exhibiting excellent biocompatibility. Further, it was estimated the capability of twofold acridine orange/ethidium bromide (AO/EB) staining to identify the apoptotic associated changes in cancer cells. Additionally, the aggregates were successfully demonstrated as a luminescent probe for the perceptive biomolecule detection of bilirubin. On the other hand, the PS molecule was successfully utilized for protein binding and metal ion sensing studies. The interaction of bovine serum albumin (BSA) with PS molecule in DMSO was using fluorescence spectroscopic method and nature of interaction was also confirmed through molecular docking analysis. The PS molecule also acts as an excellent sensor for biologically important Fe3+ ion with detection limit of 336 nM. Overall, PS molecule can be a prospective material in biological field both in solution as well as aggregated forms. © 2019 Elsevier B.V.