190 likes | 478 Views
Fabricating Chiral Nano Needle By Laser Optical Vortex. Toshiro Abe Marjam Memarpuri. Properties of Lasers Background.
E N D
Fabricating Chiral Nano Needle By Laser Optical Vortex Toshiro Abe Marjam Memarpuri
Properties of LasersBackground Fig. 1: 1. Highmonochromaticity, coherence and directionality, compared to ordinary sources of light that can allow laser light to focus towards the diffraction limit. 2. Pulsed beam (fs~ns):pulse energy is equal to the average power divided by the repetition rate. These two futures provide laser with ability to melt metals. High Peak energy
Optical Vortex Fig. 2 : Ordinary laser versus optical vortex Optical Vortex= the light which has orbital angular momentum(L) Total angular momentum J=L+S Ref. : http://iphys3-ap.eng.hokudai.ac.jp
How to Fabricate structures • Peak power = Average PWR / pulse width • Light angular momenta directly force on sample. Fig. 3: Experimental setup for the ablation. Ref.: T. Omatsu and R. Morita, Light twists a material on the nanoscale, 21 August 2013, SPIE Newsroom. DOI: 10.1117/2.1201308.004959
Ablation Result (SEM image) ( a,c,e) :Twisted nano needle was fabricated by the Optical vortex with a total angular momentum,j,of-2(Clockwise) (b,d,f) :Twisted nano needle was fabricated by the Optical vortex with a total angular momentum,j,of 2 (counter-clockwise) Can transfer laser chirality to the materials! Ref.: T. Omatsu and R. Morita, Light twists a material on the nanoscale, 21 August 2013, SPIE Newsroom. DOI: 10.1117/2.1201308.004959.
Chirality These two structures are mirror images of each other • Chiral molecules have different optical, chemical and biological properties. • Ex. : Orange and Lemon are the same molecules but enantiomers. • Many molecules in the human bodies of living beings are enantiomers themselves.
Applications Chiral nanoneedles could be used in: • Nanoscale imaging systems like (AFM) Atomic force microscopes and (STM) scanning tunneling microscopes , sensors. • Possibility to chirally select chemical reactions on plasmonic nanostructures. • Selectivity and identity of chiral chemical composites. • Possibly identity of chiral drugs. • Planar chiral metamaterials. Ref.: T. Omatsu and R. Morita, Light twists a material on the nanoscale, 21 August 2013, SPIE Newsroom. DOI: 10.1117/2.1201308.004959.
ApplicationsGold nanoneedles • Aligned gold nanoneedle arrays for surface-enhanced Raman scattering (SERS) • A simple Ar+-ion irradiation route has been developed to prepare goldnanoneedlearrays. • Nanoneedlesexhibited very sharp tips with an apex diameter of 20 nm. • Arrays were evaluated as potential SERS substrates using malachite (Cu2CO3(OH)2) green molecules. • A new technique for producing controllable and reproducible SERS substrates potentially applicable for chemical and biological assays. Ref.: Y. Yang et al., Aligned gold nanoneedle arrays for surface-enhanced Raman scattering , NANOTECHNOLOGY; AUG 13, 2010, p. 21-32.
ApplicationsSilver nanoneedles Controlled fabrication of silver nanoneedles array for SERS and rapid detection of narcotics • Novel SERS with high activity are ideal for novel SERS sensors, which detect illegal narcotics and explosives. Ref.: Y. Yang et al., Controlled fabrication of silver nanoneedles array for SERS and their application in rapid detection of narcotics, NANOSCALE; 2012, 4 8, p2663-p2669
ApplicationsSilver nanoneedles • A simple Ar+-ion sputtering route was developed to fabricate well aligned silvernanoneedles arrays on silicon substrates. • With high substrate sensitivity in 3 s can detect and becomes an important analytical technique in forensic laboratories. Ref.: Y. Yang et al., Controlled fabrication of silver nanoneedles array for SERS and their application in rapid detection of narcotics, NANOSCALE; 2012, 4 8, p2663-p2669
Applicationsantibody-functionalized nanoneedle Evaluation of the actin cytoskeleton state using an antibody-functionalized nanoneedle and an AFM • Atomic Force Microscopy (AFM) was used to develop a cell diagnosis technique. • An ultra thin sharpened 200 nm nanoneedle was inserted into the living cell without affecting its viability. Ref. AFM: 1. Loparic M. et al. (2010), Biophysical Journal 98, 2731–2740.2. Plodinec M. et al. (2012), Nature Nanotechnology 7, 757–765. Ref.: Y. R. Silberberg et al., Evaluation of the actin cytoskeleton state using an antibody-functionalized nanoneedle and an AFM, DOI: 10.1016/j.bios.2012.06.044.
Applicationsantibody-functionalized nanoneedle • Nanoneedle was functionalised with antibody to measure unbinding forces, specific mechanical interactions and intracellular content of the cell, during evacuating nanoneedle in the cell. • Possible beneficial technique for the evaluation of cytoskeleton conditions in health and disease, for the selection of specific cells according to their intracellular protein contents, without the need for introduction of marker proteins into the cell.
ApplicationsChirality and drugs Ref.: www.alltomvetenskap.se/nyheter/spegelvanda-molekyler-skapar-oreda-i-naturen. • Neurosedyn (Thalidomide) gave 10000 infants malformations and its mirror image, which is a drug and has sedating effects.
ApplicationsChirality and drugs • 1957 a drug called Thalidomide (Contergan, in Sweden Neurosedyn) was released in germany. • Prescribed as sedative or hypnotic to cure anexity and insomnia. • Later used for nausea to relieve sickness in pregnant women. • 1960 became a ”over the counter ” drug with no prescription required. • Shortly after up to 7000 infants were born with malformation of the limbs (phocomelia). • Throghout Europe, Australia, United States 10000 infants were reported with phocomelia, only 50% survived. • Since then development av more structured drug regualtions and control over drug use, ex. enantiomers of stereoisomeric drugs are required to be studied accurately. Ref.: www.wikipedia.org
Chiral Nanoneedles Thank you!
References • Ref. Figur :http://iphys3-ap.eng.hokudai.ac.jp/ • Ref.: T. Omatsu and R. Morita, Light twists a material on the nanoscale, 21 August 2013, SPIE Newsroom. DOI: 10.1117/2.1201308.004959. • Ref.: Y. Yang et al., Aligned gold nanoneedle arrays for surface-enhanced Raman scattering , NANOTECHNOLOGY; AUG 13, 2010, p. 21-32. • Ref.: Y. Yang et al., Controlled fabrication of silver nanoneedles array for SERS and their application in rapid detection of narcotics, NANOSCALE; 2012, 4 8, p2663-p2669. • Ref. AFM: 1. Loparic M. et al. (2010), Biophysical Journal 98, 2731–2740.2. Plodinec M. et al. (2012), Nature Nanotechnology 7, 757–765. • Ref.: Y. R. Silberberg et al., Evaluation of the actin cytoskeleton state using an antibody-functionalized nanoneedle and an AFM, DOI: 10.1016/j.bios.2012.06.044. • Ref.: www.alltomvetenskap.se/nyheter/spegelvanda-molekyler-skapar-oreda-i-naturen. • Ref.: www.wikipedia.org