Bio-inspired Self-Assembly of Micro and Nano-Structures for Sensing and Electronic Applications

2002 ◽  
Vol 739 ◽  
Author(s):  
H. McNally ◽  
S. W. Lee ◽  
D. Guo ◽  
M. Pingle ◽  
D. Bergstrom ◽  
...  

ABSTRACTBio-inspired assembly, through the use of bio-molecules such as DNA and proteins, will play a critical role in the advancement of novel sensing techniques and for the realization of heterogeneous integration of materials. For many of these applications, such as antibody-based biosensor and the study of controlled cell growth, DNA and protein patterning techniques are crucial. We will present an update of our work on protein patterning techniques using microelectronic fabrication, DNA hybridization and biotin-streptavidin pairing. To show its application in biological inspired self-assembly, this technique was used successfully in the self-assembly of 20 nm streptavidin conjugated gold particles. In addition, the integration of nano-and micro-scale heterogeneous materials is very important for novel material synthesis and electro-optic applications. We will present an update on our work to assemble silicon electronic devices using DNA/charged molecules and electric fields. Devices are fabricated, released, charged with molecules, and subsequently manipulated in electric fields. The techniques described can be used to integrate the hybrid devices such as nano- or micro-scale resistors, PN diodes, and MOSFETs on silicon or other substrates such as glass, plastic, etc.

2002 ◽  
Vol 735 ◽  
Author(s):  
D. Guo ◽  
H. McNally ◽  
M. Pingle ◽  
D. Bergstrom ◽  
R. Bashir

ABSTRACTProtein patterning techniques are crucial for the development of antibody-based biosensor and the study of controlled cell growth. This paper discusses a protein patterning technique based on microelectronic fabrication, DNA hybridization and biotin-streptavidin pair. A gold-on-silicon-dioxide substrate with micron size pattern was fabricated with photolithography and lift-off process. The average surface roughness of the gold pattern is 4.3 nm, measured by contact mode AFM. Thiol derivatized single stranded DNA was attached to the gold pattern surface by the chemical bonding between gold atom and sulfur atom. Surface attached DNA was then hybridized with a biotin conjugated complementary DNA sequence. Thus, the gold pattern was translated into a biotin pattern with similar resolution. Fluorescein conjugated streptavidin was patterned as demonstration. Fluorescence microscopy shows relative uniform streptavidin coverage of micron resolution and low background non-specific binding. The proposed protein patterning technique takes advantage of the high resolution of modern microelectronic fabrication. It has the potential of reaching sub-micron resolution. The biotin-streptavidin pair provides extremely specific and stable linking for protein immobilization. To show its application in biological inspired self-assembly, this technique was used successfully in the self-assembly of 20 nm streptavidin conjugated gold particles.


2002 ◽  
Vol 761 ◽  
Author(s):  
D. Guo ◽  
H. McNally ◽  
M. Pingle ◽  
D. Bergstrom ◽  
R. Bashir

ABSTRACTProtein patterning techniques are crucial for the development of antibody-based biosensor and the study of controlled cell growth. This paper discusses a protein patterning technique based on microelectronic fabrication, DNA hybridization and biotin-streptavidin pair. A gold-on-silicon-dioxide substrate with micron size pattern was fabricated with photolithography and lift-off process. The average surface roughness of the gold pattern is 4.3 nm, measured by contact mode AFM. Thiol derivatized single stranded DNA was attached to the gold pattern surface by the chemical bonding between gold atom and sulfur atom. Surface attached DNA was then hybridized with a biotin conjugated complementary DNA sequence. Thus, the gold pattern was translated into a biotin pattern with similar resolution. Fluorescein conjugated streptavidin was patterned as demonstration. Fluorescence microscopy shows relative uniform streptavidin coverage of micron resolution and low background non-specific binding. The proposed protein patterning technique takes advantage of the high resolution of modern microelectronic fabrication. It has the potential of reaching sub-micron resolution. The biotin-streptavidin pair provides extremely specific and stable linking for protein immobilization. To show its application in biological inspired self-assembly, this technique was used successfully in the self-assembly of 20 nm streptavidin conjugated gold particles.


Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Yannick Minet ◽  
Hans Zappe ◽  
Ingo Breunig ◽  
Karsten Buse

Whispering gallery resonators made out of lithium niobate allow for optical parametric oscillation and frequency comb generation employing the outstanding second-order nonlinear-optical properties of this material. An important knob to tune and control these processes is, e.g., the linear electro-optic effect, the Pockels effect via externally applied electric fields. Due to the shape of the resonators a precise prediction of the electric field strength that affects the optical mode is non-trivial. Here, we study the average strength of the electric field in z-direction in the region of the optical mode for different configurations and geometries of lithium niobate whispering gallery resonators with the help of the finite element method. We find that in some configurations almost 100% is present in the cavity compared to the ideal case of a cylindrical resonator. Even in the case of a few-mode resonator with a very thin rim we find a strength of 90%. Our results give useful design considerations for future arrangements that may benefit from the strong electro-optic effect in bulk whispering gallery resonators made out of lithium niobate.


Ionics ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 1611-1618
Author(s):  
Xiaowen Ge ◽  
Xiaomei Du ◽  
Yin Sun ◽  
Junjie Zhang ◽  
Zhongyu Qiu ◽  
...  

Soft Matter ◽  
2014 ◽  
Vol 10 (45) ◽  
pp. 9110-9119 ◽  
Author(s):  
Hanumantha Rao Vutukuri ◽  
Frank Smallenburg ◽  
Stéphane Badaire ◽  
Arnout Imhof ◽  
Marjolein Dijkstra ◽  
...  

2010 ◽  
Vol 84 (18) ◽  
pp. 9350-9358 ◽  
Author(s):  
Alexis Huet ◽  
James F. Conway ◽  
Lucienne Letellier ◽  
Pascale Boulanger

ABSTRACT The Siphoviridae coliphage T5 differs from other members of this family by the size of its genome (121 kbp) and by its large icosahedral capsid (90 nm), which is organized with T=13 geometry. T5 does not encode a separate scaffolding protein, but its head protein, pb8, contains a 159-residue aminoterminal scaffolding domain (Δ domain) that is the mature capsid. We have deciphered the early events of T5 shell assembly starting from purified pb8 with its Δ domain (pb8p). The self assembly of pb8p is regulated by salt conditions and leads to structures with distinct morphologies. Expanded tubes are formed in the presence of NaCl, whereas Ca2+ promotes the association of pb8p into contracted tubes and procapsids. Procapsids display an angular organization and 20-nm-long internal radial structures identified as the Δ domain. The T5 head maturation protease pb11 specifically cleaves the Δ domain of contracted and expanded tubes. Ca2+ is not required for proteolytic activity but for the organization of the Δ domain. Taken together, these data indicate that pb8p carries all of the information in its primary sequence to assemble in vitro without the requirement of the portal and accessory proteins. Furthermore, Ca2+ plays a key role in introducing the conformational diversity that permits the formation of a stable procapsid. Phage T5 is the first example of a viral capsid consisting of quasi-equivalent hexamers and pentamers whose assembly can be carried out in vitro, starting from the major head protein with its scaffolding domain, and whose endpoint is an icosahedral T=13 particle.


2011 ◽  
Author(s):  
Huma Ismail ◽  
Ampalavanapillai Nirmalathas ◽  
Efstratios Skafidas

2021 ◽  
Author(s):  
Huajun Xu ◽  
Delwin L Elder ◽  
Lewis E Johnson ◽  
Wolfgang Heni ◽  
Yovan de Coene ◽  
...  

This study demonstrates enhancement of in-device electro-optic activity via a series of theory-inspired organic electro-optic (OEO) chromophores based on strong (diarylamino)phenyl electron donating moieties. These chromophores are tuned to minimize...


Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2824 ◽  
Author(s):  
Kunpeng Feng ◽  
Jiwen Cui ◽  
Xun Sun ◽  
Hong Dang ◽  
Tangjun Shi ◽  
...  

Three-dimensional micro-scale sensors are in high demand in the fields of metrology, precision manufacturing and industry inspection. To extend the minimum measurable dimension and enhance the accuracy, a tapered four-cores fiber Bragg grating (FBG) probe is proposed. The sensing model is built to investigate the micro-scale sensing characteristics of this method and the design of the tapered stylus is found to influence the accuracy. Therefore, a π/2 phase-shift point is introduced into the FBGs comprised in the probe to suppress spectrum distortion and improve accuracy. Then, the manufacturing method based on capillary self-assembly is proposed to form the probe and the critical length to form a square array for four cylindrical fibers is verified to be effective for the tapered fibers. Experimental results indicate that the design of the tapered stylus can extend the minimum measurable dimension by twofold and has nearly no influence on its sensitivity. The three-dimensional measurement repeatability is better than 31.1 nm and the stability is better than 200 nm within once measuring process. Furthermore, the measurement precision of the three-dimensional micro-scale measurement results is less than 150 nm. It would be widely used in measuring micro-scale features for industry inspection or metrology.


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