Search query: Photoluminescent semiconductor nanocrystals for fingerprint detection

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abstract: The concept of utilizing photoluminescent semiconductor nanocrystals for latent fingerprint detection, especially in concert with phase resolved imaging for background fluorescence suppression, is reduced to practice with CdS nanocrystals that are capped with dioctyl sulfosuccinate. The nanocrystals are dissolved in heptane or hexane and are applied in much the same way as staining with fluorescent dye, on articles that have been pre fumed with cyanoacrylate ester and also on the sticky side of electrical tape without pre fuming. Since CdS can form a photoluminescent nanocomposite with dendrimers, a feasibility examination of dendrimer tagging of fingerprints has also been conducted.
author_names: E Roland Menzel

Steven M Savoy

Sydney J Ulvick

Kwan H Cheng

Russell H Murdock

Mark R Sudduth
title: Photoluminescent semiconductor nanocrystals for fingerprint detection.
venue: Journal of forensic sciences
year: 2000

abstract: CdS/dendrimer nanocomposites with a range of concentrations of the photoluminescent semiconductor nanocluster and the dendrimer are prepared in methanol and 1:9 methanol:water solutions. The solutions are utilized for detection of cyanoacrylate ester fumed and unfumed fingerprints on polyethylene and aluminum foil.
author_names: E Roland Menzel

Masahisa Takatsu

Russell H Murdock

Kimberly K Bouldin

Kwan H Cheng
title: Photoluminescent CdS/dendrimer nanocomposites for fingerprint detection.
venue: Journal of forensic sciences
year: 2000

abstract: Uniform and well dispersed photoluminescent semiconductor CdSe (Cadmium selenium) QDs (Quantum dots) were in situ prepared by taking G4.0 NH2 PAMAM(polyamidoamine) dendrimers as inner templates in water and methanol respectively. The prepared solutions containing photoluminescent semiconductor CdSe QDs were utilized for detection of unfumed oil fingerprints on tinfoil. The results show that unfumed latent fingerprints treated with prepared CdSe/PAMAM nanocomposites both displayed yellow emission and the latent fingerprints were detected clearly, while treated with CdSe/PAMAM composites in water manifested stronger emission compared with those treated with CdSe/PAMAM composites in methanol; Also, the veins of fingerprints treated with CdSe/PAMAM nanocomposites in methanol became slim because of the dissolution of methanol to oil components in fingerprints.
author_names: Yu-juan Jin

Yunjun Luo

Yuan Feng Wang

Hui Sun

Hao Zhang

Di Jin
title: Effect of Solvent to Fingerprint Detection by Photoluminescent CdSe/PAMAM Nanocomposites
year: 2013

abstract: Fluorescent sensors benefit from high signal to noise and multiple measurement modalities, enabling a multitude of applications and flexibility of design. Semiconductor nanocrystal quantum dots (QDs) are excellent fluorophores for sensors because of their extraordinary optical properties. They have high thermal and photochemical stability compared to organic dyes or fluorescent proteins and are extremely bright due to their large molar cross sections. In contrast to organic dyes, QD emission profiles are symmetric, with relatively narrow bandwidths. In addition, the size tunability of their emission color, which is a result of quantum confinement, make QDs exceptional emitters with high color purity from the ultra violet to near infrared wavelength range. The role of QDs in sensors ranges from simple fluorescent tags, as used in immunoassays, to intrinsic sensors that utilize the inherent photophysical response of QDs to fluctuations in temperature, electric field, or ion concentration. In more complex configurations, QDs and biomolecular recognition moieties like antibodies are combined with a third component to modulate the optical signal via energy transfer. QDs can act as donors, acceptors, or both in energy transfer based sensors using Forster resonance energy transfer (FRET) nanometal surface energy transfer (NSET) or charge or electron transfer. The changes in both spectral response and photoluminescent lifetimes have been successfully harnessed to produce sensitive sensors and multiplexed devices. While technical challenges related to biofunctionalization and the high cost of laboratory grade fluorimeters have thus far prevented broad implementation of QD based sensing in clinical or commercial settings, improvements in bioconjugation methods and detection schemes, including using simple consumer devices like cell phone cameras, are lowering the barrier to broad use of more sensitive QD based devices.
author_names: Margaret Chern

Joshua C Kays

Shashi Bhuckory

Allison M Dennis
title: Sensing with photoluminescent semiconductor quantum dots.
venue: Methods and applications in fluorescence
year: 2019

abstract: Uniform and well dispersed photoluminescent semiconductor CdS (cadmium sulfide) QDs (quantum dots) were in situ prepared inside Generation 4.0 NH(2) PAMAM (polyamidoamine) dendrimers in methanol, methanol and water mixed solutions of volume ratio 1:9, respectively. The prepared solutions containing photoluminescent semiconductor CdS QDs were utilized for detection of cyanoacrylate ester fumed fingerprints on tinfoil. The results show that fumed latent fingerprints treated with prepared CdS/PAMAM nanocomposites in methanol, 1:9 methanol:water mixed solutions emit pale yellow green and orange luminescence respectively under ultraviolet excitation of 365 nm from an UV LED. Fumed fingerprints were successfully detected with good resolving rate and the mechanism was studied in detail.
author_names: Yu-juan Jin

Yunjun Luo

Guoping Li

Jie Li

Yuan-Feng Wang

Rui-qin Yang

Wenting Lu
title: Application of photoluminescent CdS/PAMAM nanocomposites in fingerprint detection.
venue: Forensic science international
year: 2008

abstract: Uniform and well dispersed photoluminescent semiconductor CdSe(Cadmium selenium) QDs(Quantum dots) were in situ prepared stabilized by G4.0 NH2 PAMAM dendrimers in water and effects of metallic ions such as Zn2+ Cd2+ Cu2+ Ag+ Pb2+ K+ Na+ on the photoluminescence(PL) properties of CdSe QDs were studied using spectrophotometric titration. The results show that Zn2+ and Cd2+ ions enhance the PL intensity of CdSe QDs, Cu2+ Ag+ and Pb2+ ions quench the PL intensity, while K+ and Na+ ions have no obvious effects. Those are attributed to the surface modification of CdSe QDs. Excess Cd2+ ions can reduce the non combination centers, increase the passivation of PAMAM on the surface of CdSe QDs, and form a Schottky like barrier which enhanced the PL efficiency. Excess Zn2+ ions can also increase the PL intensity of CdSe QDs in the same way as Cd2+ ions because of the much similar lattice parameters of CdSe and ZnSe. However, a CuSe, Ag2Se or PbSe shell on CdSe QDs emerges due to the substitution of Cd2+ ions, which leads to the decrease of band edge emmiting of CdSe QDs. And the quenching effect of Ag+ is stonger than Cu2+ and Pb2+ because of the lower solubility of Ag2Se formed on the surface of CdSe QDs. Oil latent fingerprints deposited on tinfoil surface treated with CdSe/dendrimer NCs(Nanocomposites) Cd2+ CdSe/ PAMAM NCs and Zn2+ CdSe /PAMAM NCs emitted bright yellow photoluminescence under ultraviolet excitation of 365nm from an UV LED in the dark. among, fingerprint treated with Cd2+ CdSe/dendrimer NCs and Zn2+ CdSe /PAMAM NCs was detected with better resolving rate.
author_names: Yu-juan Jin

Yunjun Luo

Guo Zhi Xu

Biao Yang
title: Effects of Metallic Ions on Photoluminescence Properties of CdSe/PAMAM Nanocomposites and their Application in Fingerprint Detection
year: 2011

abstract: The potential of using water soluble photoluminescent nanoparticles of different sizes for latent fingerprint detection has been explored. In this pilot study, green (582 nm) and red (755 nm) CdTe nanocrystals coated with thioglycolic acid were used. Latent fingerprints on aluminum and glass surfaces were successfully labeled with these nanoparticles for time periods ranging from 30 min to 24 h. The labeling is probably due to the amidation reaction between the surface carboxylic groups of the nanoparticles with the amine groups of the biomaterials present in the fingerprint residues. The 582 nm emitting nanoparticles appeared to better label the fingerprint ridges than did the 755 nm emitting ones for both surfaces. However, the 755 nm emitting nanoparticles were able to target the sweat pores within the ridges of the fingerprints. Other than high quantum yield and photostability, the tunable emission wavelength, the narrow bandwidth, the customizable surface characteristics, and the relatively long fluorescence decay lifetime of these nanoparticles are useful and necessary features for the future development of ultra sensitive, target specific, background suppressed latent fingerprint detection for forensic applications.
author_names: Kwan Hon Cheng

Jacob Ajimo

Wei Chen
title: Exploration of functionalized CdTe nanoparticles for latent fingerprint detection.
venue: Journal of nanoscience and nanotechnology
year: 2008

abstract: Abstract Non cadimum photoluminescent I III VI semiconductor nanocrystals have attracted increasing attention due to their low toxicity, extraordinary optical and electronic properties. Herein, water soluble quaternary Cu In Zn S quantum dots (CIZS QDs) with tunable emission from 535 nm to 645 nm were successfully synthesized via ecofriendly one pot aqueous method. The full width at half maximum (FWHM) of the emissions are about 68 nm 88 nm, which are rather narrow among Cu based semiconductors and preferred to facilitate improving color purity. The photoluminescence of water soluble QDs was enhanced by ZnS coating with the absolute quantum yield (QY) up to 30.8% Further, a novel fluorescent sensor for Cu2+ detection was developed based on the alteration of intrinsic optical properties of the CIZS/ZnS QDs after cation exchange at room temperature within 10 min, presenting a linear range of 0.020 20 mM and a detection limit down to 6.7 nM. Mechanism studies revealed that the QDs served as the template for cation exchange, through UV vis absorption and fluorescence spectra in combination with the chemical composition and time resolved photoluminescence decay analysis. Ions interference experiments demonstrated the good selectivity of the QDs towards Cu2+ and the sensor showed comparable accuracy to ICP AES method as well as good performance in real sample detection, manifesting the reliability of the current strategy for sensing Cu2+ mildly and rapidly.
author_names: Mingxia Jiao

Yun Li

Yuxiu Jia

Zhen Yang

Xiliang Luo
title: Aqueously synthesized color tunable quaternary Cu In Zn S quantum dots for Cu(II) detection via mild and rapid cation exchange
venue: Sensors and Actuators B: Chemical
year: 2019

abstract: Carbon nanomaterials, including carbon nanotubes, fullerenes, graphene, and porous carbons, have attracted tremendous attention owing to their unique properties and potential applications, including adsorption, separation, catalysis, gas storage, and electrode materials, among others. More recently, carbon nanomaterials with photoluminescent properties have presented exciting opportunities in the search for benign "nanolanterns" that are highly desired in bioimaging, disease detection, and drug delivery. Compared to organic dyes and fluorescent semiconductor nanocrystals (quantum dots) photoluminescent carbon nanomaterials are superior in chemical inertness and possess distinct benefits, such as no optical blinking, low photobleaching, low cytotoxicity, and excellent biocompatibility. Thus far, numerous approaches, including arc discharge, laser irradiation, electrochemical synthesis, pyrolysis, and hydrothermal methods have been developed to prepare these versatile materials. However, there is still a bottleneck for progress in understanding and controlling the morphology, size, and surface chemistry of the resultant products with high quantum yields (QYs) which impede their practical applications. Moreover, exploration of photoluminescent carbon nanomaterials with high QYs 30 for use as fluorescent chemosensors to monitor and image biological processes, still remains in an early stage. It has been demonstrated that functionalizing fluorescent carbon nanomaterials with nitrogen groups can significantly enhance their properties and expand their novel applications. Despite several successes in this area, it is still of great urgency to develop simple and effective methods to synthesize novel nitrogen doped photoluminescent carbon nanomaterials with uniform morphology and high QYs. Recently, there has been a trend to synthesize carbonbased materials from biomass materials, as these are inexpensive, easy to obtain, and nontoxic, among other properties. A typical biomass material, more than 480 000 tons per year of cocoon silk produced by the Bombyx mori silkworm is cultivated all over the world. It is composed of fibrous proteins (fibroin) and sericin, which surrounds the fibroin fibers and cements them together. Moreover, silk fibroin can be easily dissolved and then regenerated into new materials. Herein, we present a simple hydrothermal treatment of cocoon silk to prepare water soluble, nitrogendoped, photoluminescent polymer like carbonaceous nanospheres (CNSs) in water, without any additives, such as salts, acids, or bases. Our results show that the resultant CNSs possess a uniform morphology, with a size of ca. 70 nm, plentiful oxygen and nitrogen functional groups, and excellent and stable fluorescent properties with a QY of ca. 38 Moreover, the CNSs can be applied as a fluorescent probe for the detection of Hg and Fe ions. Mostly important, we further demonstrate that such photoluminescent CNSs exhibit low toxicits and are biocompatible for use with in vivo imaging and as biosensors in living cells, as well as in tissues at a depth of 60 120 mm. Hydrothermal treatment of cocoon silk at 200 8C leads to a yellow dispersion of the CNSs. A transmission electron microscopy (TEM) image (Figure 1a) shows that the CNSs are uniform in size (an average of ca. 70 nm) and welldispersed. A dynamic light scattering (DLS) plot (Supporting Information, Figure S1) further demonstrates the monodis
author_names: Wei Qin Li

Zehui Zhang

Biao Kong

Shan-shan Feng

Jinxiu Wang

Lingzhi Wang

Jianping Yang

Fengyu Zhang

Peiyi Wu

Dongyuan Zhao
title: Simple and green synthesis of nitrogen doped photoluminescent carbonaceous nanospheres for bioimaging.
venue: Angewandte Chemie
year: 2013

abstract: Abstract High throughput determination of trace contaminants has attracted a great deal of attention due to their high toxicity, hyperstability and ultra low level. Among various analytical methods developed during the past few decades, nanosensoring techniques have become increasingly popular due to their potential for portable, rapid and real time detection. Quantum dots (QDs) are colloidal semiconductor nanocrystals with excellent photoluminescent properties, high quantum yields and high resistance to photobleaching. Recently, QD based photoluminescent nanosensing (plnanosensing) techniques have provided new advances in the field of contaminant determination for environmental monitoring and food quality control. This review focuses on the improvements in the analytical performances of QD based plnanosensing techniques in order to achieve on site rapid screening of multiple contaminants. Critical factors along with some difficulties in high throughput determination of trace contaminants are summarized. Furthermore, the main strategies for enhancing the analytical performance of QD based plnanosensors based on the characteristics and difficulties of trace analysis are highlighted. Finally, we discuss the difficulties in association with the use of QD based optosensors in trace analysis and the prospective applications of this novel analytical technique in the future.
author_names: Weijun Kong

Xihui Yang

Meihua Yang

Haosen Zhou

Zhen Ouyang

Ming Zhao
title: Photoluminescent nanosensors capped with quantum dots for high throughput determination of trace contaminants: Strategies for enhancing analytical performance
year: 2016