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Questions related from Adam Hughes
The course of evolution is steered by selection pressure. For example, giraffes with the longest necks can reach more food, so the "long neck" trait is favored in reproduction. Over large time...
07 July 2017 9,344 4 View
We have had success making self-assembled gold nanoparticle monolayers on glass through an amine-silane layer. We're exploring a new protocol, which requires a carboxylated glass surface, and...
05 May 2015 563 10 View
Hello, We make self-assembled monolayers of gold nanoparticles on aminesilane glass substrate, and get pretty high quality monolayers. However, after we coat the gold particles in certain...
05 May 2015 3,027 7 View
I'm looking to purchase anti-BSA hosted in Rabbit. I've seen a variety of vendors and prices for this product.Life technologies: 159.00...
04 April 2015 956 2 View
We've successfully computed the reflectance from a multilayered system of glass, organosilanes and gold nanoparticle films (SEE ATTACHED FIGURE) using the transfer matrix method, and treating the...
04 April 2015 6,115 4 View
In regard to label-free assays developed to measured interactions between some target molecule and a surface, I often see the Langmuir isotherm/1:1 binding model applied to systems without...
04 April 2015 8,107 5 View
We need to stir a 200-300uL volume in a microtube, and currently are relying on flea stirrers; however, even the smallest stirrer we can find always needs cut with bolt cutters to get a small...
04 April 2015 9,169 6 View
Hello, I'm trying to put together a dissertation in Biophysics. I have several papers that I'd like to go into the thesis, similar to a stapled thesis, and my school does allow for this type of...
03 March 2015 2,879 1 View
I'm writing a paper in which we are comparing the response profile of various types of biosensors, and I'd like to do a collage image that shows the response curves for the various systems in...
03 March 2015 6,969 4 View
Imagine a paper X builds a new sensor, and then uses the new sensor to detect protein Z. When citing paper X, I might want to point out that they've build a new sensor. EG:"New sensors have been...
03 March 2015 4,962 35 View
I've been using effective medium theories to represent an array of nanomaterials in a layer of glass as an approximate, homogenous medium. This actually works quite well for our intents and...
02 February 2015 7,167 10 View
I've done calculations using Fresnel's equations and the transfer method matrix calculation on layers of thin films. These ray-optics calculations make sense to me, but I don't have a good...
01 January 2015 5,498 3 View
Hi, I've been reading about ellipsometry and think I understand how to measure the parameters Delta and Phi. What I'm having trouble finding is a comprehensive resource on how to infer thickness...
01 January 2015 7,839 8 View
I've been using the Sopra database for files that have the index of refration vs. wavelength for many materials: http://www.sspectra.com/sopra.htmlAre there other free databases out there that...
12 December 2014 4,113 9 View
I'm modeling a system which requires effective mixing theories in two places. First, I'm modeling a shell of proteins around gold nanoparticles as a homogenous mixed material of protein (n=1.5 or...
12 December 2014 8,583 4 View
Hi, I'm trying to perform an honest assessment of the state of open-source software for simulations of plasmonic systems. For example, simulating the transmittance/reflectance off of an optical...
12 December 2014 8,137 6 View
I'm trying to figure out if in general, if I perform contrast enhancement preprocessing (eg. histogram equilization, adaptive equilization or constrast stretching), how this will impact the...
11 November 2014 7,603 15 View
Hi, We're doing some LSPR studies measuring antigen-IgG binding, and I'm trying to learn the general properties of IgG's. From the few I've studied carefully, they have similar masses...
11 November 2014 6,298 5 View
Imagine I have a dataset of N spectra (eg t1, t2, ... tN), each ranging over some set of M wavelengths (e.g. 200nm-800nm). Let's say the data set has three distinct, fairly broad peaks, A, B and...
11 November 2014 1,085 5 View
Hi, We've noticed significant contamination on SEM images of gold-coated optical fibers. We've determined the contamination is likely happening during the protein detection phase, as imaging...
10 October 2014 695 8 View
Hi, We are imaging self-assembled nanoparticles on optical fibers. Our surface is highly charged, and tends to attract a lot of junk. We've eliminated a lot of contamination believe it or not,...
10 October 2014 1,940 11 View
Hi, We've been using EDC/NHS activation to covalently attach proteins to a carboxylated gold surface with fair success. We'd like to begin immobilizing IgG's, and I'm worried about controlling...
09 September 2014 4,444 12 View
This is a very specific question. In label-free assays like those used in Biacore, one often uses a carboxymethylated chip surface which tends to have a strong net negative charge. In the SPR...
09 September 2014 7,792 5 View
Hi, I have an aminosilane layer on glass which has a net negative charge. I'm curious if you think that adding NHS to this layer should cause a permanent blocking of the charged amines? I know...
08 August 2014 690 2 View
We are trying to coat gold nanoparticles with carboxy-terminated polyethylene glycols. The nanoparticles are affixed to a surface, so this is not in free solution and aggregation is not a...
08 August 2014 10,072 5 View
Hi, We've put proteins through covalent immobilization on gold paticles on substrates and would like to store the substrates longterm. I've seen that vendors often sell pre-conjugated...
08 August 2014 8,778 2 View
We are looking to cut microorganism contamination in our experiments, which involve leaving charged glass samples in buffers/water overnight. Our buffers are usually PBS and MES. I am looking for...
07 July 2014 4,165 5 View
Hi, I have gold nanopaticles affixed to a glass surface and am trying to find an optimal protocol for coating with PEG molecules, in particular, CTPEG12 and MTPEG4...
07 July 2014 4,777 6 View
I am interested in learning more about which standard proteins are commonly found in Western Blot kits. In particular, I'm most curious in regard to the 30-80kDA range of sizes. We'd like to...
05 May 2014 3,401 5 View
We are looking to measure a specific interaction between NeutrAvidin and an antibody. We've read that Streptavidin does not appreciably bind antibodies specific to Avidin, but there is no...
05 May 2014 3,932 3 View
I am troubleshooting a biosensor with gold nanoparticles with and without various small chain thiol coating molecules. We are trying to assess the efficacy of the coatings, but have primarily...
05 May 2014 397 6 View
I have been using BSA to do control experiments on a plasmonic biosensor with gold nanoparticles of various coatings. BSA tends to stick irreversibly to our nanoparticles because of its...
05 May 2014 8,416 4 View
We are looking at set of protein sequences from the purple sea urchin, and trying to identify the function of a subset of 200 or so proteins in the genome that have a very specific domain. From...
05 May 2014 1,736 20 View
I am designing some controls for an LSPR experiment using BSA and another protein of comparable size. BSA is very "sticky" (hydrophobic regions, surface thiol, highly charged), and so we'd like to...
05 May 2014 9,706 1 View
I have several stock powders that I'd like to store for as long as possible in a refridgerator. We have limited access to N2, so what I've been doing is distributing the stock powder into smaller...
04 April 2014 8,399 1 View
I'm trying to develop an experiment for measuring BSA-AntiBSA binding using polyclonal primary IgG anti-bsa antibodies. I see that it is sold purified or in serum. In regard to the...
04 April 2014 814 4 View
We've developed a biosensor based on plasmonic resonance of nanoparticles and would like to perform antibody-antigen conjugation experiments. With almost no formal biology experience, it's really...
04 April 2014 3,933 9 View
Of course my initial reaction is no, but I think there's some important discussion to be had in my naive understanding of this topic. Weka (http://sourceforge.net/projects/weka/) and Ilastik...
03 March 2014 9,580 7 View
I use SEM to image gold nanoparticles on glass surfaces. I've attached a high res image at 30000X mag. Based on the scale bar, you can see I'm sampling an area of about 15um X 10um. In my post...
12 December 2013 1,787 13 View
I have been using a Zeiss SEM for imaging 10-50nm diameter gold particles. To minimize charging, we use low energies (1 kV), and have imaged the particles in various detectors (ie in-lens and...
12 December 2013 8,387 11 View
I'm looking to publish some papers in the next few months. The research is mostly "methods and techniques", and I believe it is useful research; however, not landmark or groundbreaking. I've...
11 November 2013 1,071 5 View
I have seen in several papers people claim to get self-assembled AuNp monolayers on MPTMS (http://www.sigmaaldrich.com/catalog/product/fluka/63800?lang=en®ion=US), but the SH group is neutral...
11 November 2013 9,701 2 View
I use pirhana to clean glass fibers and slides for gold nanoparticle self-assembly experiments. The piranha frees hydroxyls on the glass, which then allow for covalent binding to various chemical...
10 October 2013 3,208 28 View
I'm depositing 22nm diameter citrate-capped AuNPs onto a glass substrate (optical fiber) through an amine-reactive covalent crosslinker ((3-Trimethoxysilylpropyl)-diethylenetriamine ). This...
10 October 2013 3,923 13 View
I am looking to control the surface deposition of AuNP's onto a glass surface by controlling the mixing density of amine-reactive silanes with non-reactive silanes. The idea is that by reducing...
10 October 2013 8,782 6 View
I am interested in using optical fibers with sharpened tips for detection in biochemical systems. We are coating the tips with metallic films or nanoparticles. I've noticed that groups that make...
05 May 2013 615 2 View
Hi all, I'm new to SERS, but have a nice fiber optic sensor that uses visible light on gold nanopaticle monolayers to measure biomolecular interactions. I am very interested in measuring SERS...
05 May 2013 1,426 3 View
I've been having good success with self-assembly on AuNP's on amine-functionalized glass surfaces. I've noticed that even with our best runs/protocols for amine functionalization, if we let the...
02 February 2013 9,383 24 View
This is one of those gritty details that never makes it into a paper. I often use Amine-capped silanes (such as 3aminopropyltrimethoxysilane- APTMS) in hopes of constructing monolayers of gold...
01 January 2013 8,879 4 View
I have been successfully depositing home-made, 30nm citrate-capped gold nanoparticles onto amine-functionalized glass surfaces. Recently, I noticed that a couple other batches of particles (one...
01 January 2013 7,483 8 View
I am using HF etching to make sharp tips on silica optical fibers and would like to hydrolyze the surface following the HF etching and then attach cross-linker molecules, which attach to the glass...
11 November 2012 10,054 4 View
I am trying to bind gold nanoparticles to functionalized glass surfaces (optical fibers in particular) and the simple protocol I use works GREAT with 3-aminopropyltrimethoxysilanes, but fails...
06 June 2012 4,529 20 View
