Quantum Dot-Based Sensors

F. Koeppel, J. K. Jaiswal, and S. M. Simon, Quantum dot-based sensor for improved detection of apoptotic cells. Nanomed., 2(1), 71-78 (2007). 

Mozafari, M., Moztarzadeh, F. (2011). Microstructural and Optical Properties of Spherical Lead Sulphide Quantum Dots-based Optical Sensors. Micro Nano Letters, lET, 6(3), 161-164. 

Koneswaran M, Narayanaswamy R (2009) L-cysteine-capped ZnS quantum dots based fluorescence sensor for Cu ion. Sens Actuators B 139 104-109... 

As can be seen, II-VI semiconductor compounds can be used as sensing materials in all types of gas sensors, including chemiresistors, SAW, heterojunction based, and optical. They can be applied to surface functionalizing and composites forming as well. The application of II-VI saniconductor compounds in quantum dots-based gas sensors will be discussed in Chap. 5 (Vol. 2). Operating characteristics of several Il-VI-based gas sensors are shown in Figs. 5.18 and 5.19. 

Chun J, Yang W, Kim JS (2011) Thermal stability of CdSe/ZnS quantum dot-based optical fiber temperature sensor. 

Particularly attractive for numerous bioanalytical applications are colloidal metal (e.g., gold) and semiconductor quantum dot nanoparticles. The conductivity and catalytic properties of such systems have been employed for developing electrochemical gas sensors, electrochemical sensors based on molecular- or polymer-functionalized nanoparticle sensing interfaces, and for the construction of different biosensors including enzyme-based electrodes, immunosensors, and DNA sensors. Advances in the application of molecular and biomolecular functionalized metal, semiconductor, and magnetic particles for electroanalytical and bio-electroanalytical applications have been reviewed by Katz et al. [142]. 

Goldman ER, Medintz IL, Whitley JL et al (2005) A hybrid quantum dot-antibody fragment fluorescence resonance energy transfer-based TNT sensor. J Am Chem Soc 127 6744-6751... 

Abstract Silver clusters, composed of only a few silver atoms, have remarkable optical properties based on electronic transitions between quantized energy levels. They have large absorption coefficients and fluorescence quantum yields, in common with conventional fluorescent markers. But importantly, silver clusters have an attractive set of features, including subnanometer size, nontoxicity and photostability, which makes them competitive as fluorescent markers compared with organic dye molecules and semiconductor quantum dots. In this chapter, we review the synthesis and properties of fluorescent silver clusters, and their application as bio-labels and molecular sensors. Silver clusters may have a bright future as luminescent probes for labeling and sensing applications. 

Goldman, E. R., I. L. Medintz, J. L. Whitley, A. Hayhurst, A. R. Clapp, H. T. Uyeda, J. R. Deschamps, M. E. Lassman, and H. Mattoussi. A hybrid quantum dot-antibody fragment fluorescence resonance energy transfer-based TNT sensor. J. Am. Chem. Soc. 127, 6744-6751 (2005b). 

CNTs and other nano-sized carbon structures are promising materials for bioapplications, which was predicted even previous to their discovery. These nanoparticles have been applied in bioimaging and drag delivery, as implant materials and scaffolds for tissue growth, to modulate neuronal development and for lipid bilayer membranes. Considerable research has been done in the field of biosensors. Novel optical properties of CNTs have made them potential quantum dot sensors, as well as light emitters. Electrical conductance of CNTs has been exploited for field transistor based biosensors. CNTs and other nano-sized carbon structures are considered third generation amperometric biosensors, where direct electron transfer between the enzyme active center and the transducer takes place. Nanoparticle functionalization is required to achieve their full potential in many fields, including bio-applications. 

A special case of nanocrystal that is comprised of a semiconductor is known as a quantum dot Typically, the dimensions of these nanostructures lie in the range 1-30 nm, based on its composition (see below). Quantum dots currently find applications as sensors, lasers, and LEDs. In fact, new high-density disks (e.g., HD-DVD and Blu-ray high-definition DVD formats) may only be read via blue lasers, which... 

The field of clusters and fullerenes represents areas of modern science where the properties are determined by the reduced coordination. This will modify the functional properties when clusters are used in disperse forms or as units in cluster assembled materials. Examples of applications can be catalysts, sensor materials, units in nanophase/nanocrystalline materials with improved mechanical, electrical, magnetic or optical properties, of cluster based materials for sun protection, solar energy conversion, as an alternative to quantum dots produced with traditional techniques, fabrication of mesoscopic systems etc. The hope is to tune the properties with cluster size, making cluster based materials with characteristics more advanced than those of conventional materials. Production of these types of cluster and exploration of their properties of free as well as deposited clusters are a challenging task of basic and applied science which will be covered in the following sections of this article. 

Zhao, Z., Arrandale, M., Vassiltsova, O. V., Petrukhina, M. A. and Carpenter, M. A. (2009) Sensing Mechanism Investigation on Semicondnctor Quantum Dot/polymer Thin Film Based Hydrocarbon Sensor. Sensor. Actual. B, 141, 26-33. 

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