scholarly journals Computational Investigations of Fixed-Free and Fixed-Fixed Types Single-Wall Carbon Nanotube Mass Sensing Biosensor

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
K. Umapathi ◽  
Yalamanchili Sangeetha ◽  
A. N. Shankar ◽  
P. Vidhyalakshmi ◽  
R. Ramkumar ◽  
...  

Using carbon nanotubes for sensing the mass in a biosensor is recently proven as an emerging technology in healthcare industry. This study investigates relative frequency shifts and sensitivity studies of various biological objects such as insulin hormone, immunoglobulin G (IgG), the most abundant type of antibody, and low-density lipoproteins (LDL) masses using the single-wall carbon nanotubes as a biomass sensor via continuum mechanics. Uniform distributed mass is applied to the single-wall carbon nanotube mass sensor. In this study, fixed-free and fixed-fixed type single-wall carbon nanotubes with various lengths of relative frequency shifts are studied. Additionally, the sensitivity analysis of fixed-free and fixed-fixed type CNT biological mass sensors is carried out. Moreover, mode shapes studies are performed. The sensitivity results show better, if the length of the single-wall carbon nanotube is reduced.

2004 ◽  
Vol 855 ◽  
Author(s):  
S. Gupta ◽  
M. Hughes ◽  
J. Robertson

ABSTRACTElectrochemical tuning of single-wall carbon nanotubes has been investigated using in situ Raman spectroscopy. We built a linear actuator from single-wall carbon nanotube mat and studied in several alkali metal (Li, Na, and K) and alkaline earth (Ca) halide solutions. The variation of bonding with electrochemical biasing was monitored using in situ Raman. This is since Raman can detect changes in C-C bond length: the radial breathing mode (RBM) at ∼190 cm−1 varies inversely with the nanotube diameter and the G band at ∼1590 cm−1 varies with the axial bond length. In addition, the intensities of both the modes vary significantly in a nonmonotonic manner pointing at the emptying/depleting or filling of the bonding and anti-bonding states - electrochemical charge injection. We discuss the variation of spectroscopic observables (intensity/frequency) of these modes providing valuable information on the charge transfer dynamics on the single-wall carbon nanotubes mat surface. We found the in-plane compressive strain (∼ -0.25%) and the charge transfer per carbon atom (fc ∼ -0.005) as an upper bound for the electrolytes used i.e. CaCl2. These results can be quantitatively understood in terms of the changes in the energy gaps between the one-dimensional van Hove singularities in the electron density of states arising possibly due to the alterations in the overlap integral of π bonds between the p orbitals of the adjacent carbon atoms. Moreover, the extent of variation of the absolute potential of the Fermi level or alternatively modification of band gap is estimated from modeling Raman intensity to be around 0.1 eV as an upper bound for CaCl2.


2019 ◽  
Vol 1 (9) ◽  
pp. 3307-3324 ◽  
Author(s):  
Jeffrey A. Fagan

Aqueous two-polymer phase extraction is described for its best-practice use to isolate single-wall carbon nanotube species.


2014 ◽  
pp. 262-318
Author(s):  
Francisco Torrens ◽  
Gloria Castellano

This chapter discusses the existence of single-wall carbon nanocones (SWNCs), especially nanohorns (SWNHs) in organic solvents in the form of clusters. A theory is developed based on a bundlet model describing their distribution function by size. Phenomena have a unified explanation in bundlet model in which free energy of an SWNC, involved in a cluster, is combined from two components: a volume one, proportional to number of molecules n in a cluster, and a surface one proportional to n1/2. A bundlet model enables describing distribution function of SWNC clusters by size. From purely geometrical differences, bundlet (SWNCs) and droplet (fullerene) models predict different behaviours. The SWNCs of various disclinations are investigated via energetic–structural analyses. Several SWNC’s terminations are studied which are different among one another because of the type of closing structure and arrangement. Packing efficiencies and interaction-energy parameters of SWNCs/SWNHs are intermediate between fullerene and single-wall carbon nanotube (SWNT) clusters.


Nanoscale ◽  
2016 ◽  
Vol 8 (17) ◽  
pp. 9304-9309 ◽  
Author(s):  
Shuo Xu ◽  
Fengqiu Wang ◽  
Chunhui Zhu ◽  
Yafei Meng ◽  
Yujie Liu ◽  
...  

The nonlinear optical response of a single-wall carbon nanotube composite is characterized across 600–2400 nm, revealing new spectral signatures of saturable absorption.


Author(s):  
Francisco Torrens ◽  
Gloria Castellano

This chapter discusses the existence of single-wall carbon nanocones (SWNCs), especially nanohorns (SWNHs) in organic solvents in the form of clusters. A theory is developed based on a bundlet model describing their distribution function by size. Phenomena have a unified explanation in bundlet model in which free energy of an SWNC, involved in a cluster, is combined from two components: a volume one, proportional to number of molecules n in a cluster, and a surface one proportional to n1/2. A bundlet model enables describing distribution function of SWNC clusters by size. From purely geometrical differences, bundlet (SWNCs) and droplet (fullerene) models predict different behaviours. The SWNCs of various disclinations are investigated via energetic–structural analyses. Several SWNC’s terminations are studied which are different among one another because of the type of closing structure and arrangement. Packing efficiencies and interaction-energy parameters of SWNCs/SWNHs are intermediate between fullerene and single-wall carbon nanotube (SWNT) clusters.


2016 ◽  
Vol 1 (4) ◽  
pp. 317-324 ◽  
Author(s):  
J. Campo ◽  
Y. Piao ◽  
S. Lam ◽  
C. M. Stafford ◽  
J. K. Streit ◽  
...  

Chemical control of the endohedral volume of single-wall carbon nanotubes (SWCNTs) via liquid-phase filling is established to be a facile strategy to controllably modify properties of SWCNTs in manners significant for processing and proposed applications.


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