PMID- 22902529
OWN - NLM
STAT- MEDLINE
DCOM- 20130213
LR  - 20161125
IS  - 1364-5528 (Electronic)
IS  - 0003-2654 (Linking)
VI  - 137
IP  - 20
DP  - 2012 Oct 21
TI  - Fabrication of an octadecylated silica monolith inside a glass microchip for 
      protein enrichment.
PG  - 4751-9
LID - 10.1039/c2an16018h [doi]
AB  - Silica-based monolithic materials have shown great promise for use as sorbent 
      materials due to their large surface area and bimodal pore size distribution. In 
      this paper, a new process for the fabrication of a silica-based monolith inside a 
      glass microchip and its modification with octadecylsilyl ligands was successfully 
      developed for use in the microchip-based solid phase extraction of proteins. 
      Monolithic porous silica without cracks was prepared by a sol-gel process, 
      followed by placement of the monolithic silica disk inside the extraction chamber 
      in the base plate of the microchip. The two plates of the glass microchip were 
      then thermally bonded at 575  degrees C for 3 hours. The silica-based monolith was not 
      affected by the thermal bonding of the two plates of the microchip. This process 
      completely avoids the problem of shrinkage in the silica skeleton during 
      preparation. The monolithic silica disk inside the glass microchip was 
      subsequently modified with octadecylsilyl (C(18)) moieties for increased protein 
      binding capacity. The performance of the microchip was evaluated using the 
      extraction of six proteins varying in molecular weight and isoelectric point, 
      namely insulin, cytochrome C, lysozyme, myoglobin, beta-lactoglobulin, and 
      hemoglobin at a concentration of 60 muM. The standard protein was mixed with a 
      double concentration of the detergent 
      3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). The results 
      show that the octadecylated silica monolith was permeable, has the ability to 
      remove impurities, and achieved a high extraction recovery of the proteins 
      (94.8-99.7%) compared with conventional octadecylated silica particles 
      (48.3-91.3%). The chip-to-chip reproducibility was assessed by calculating the 
      relative standard deviations (RSDs) for the six proteins during extraction. The 
      intra-batch and inter-batch RSDs were in the range of 2.0-4.5% and 2.9-6.4%, 
      respectively. This new microfluidic device for protein extraction may find an 
      application in the area of proteomic research.
FAU - Alzahrani, Eman
AU  - Alzahrani E
AD  - Analytical Chemistry Group, Department of Chemistry, University of Hull, UK. 
      em-s-z@hotmail.com
FAU - Welham, Kevin
AU  - Welham K
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Analyst
JT  - The Analyst
JID - 0372652
RN  - 0 (Cholic Acids)
RN  - 0 (Proteins)
RN  - 0 (octadecylsilica)
RN  - 7631-86-9 (Silicon Dioxide)
RN  - QBP25342AG (3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate)
SB  - IM
MH  - Cholic Acids/chemistry
MH  - Glass
MH  - *Microfluidic Analytical Techniques
MH  - Proteins/*isolation & purification
MH  - Proteomics
MH  - Silicon Dioxide/*chemistry
MH  - Solid Phase Extraction
EDAT- 2012/08/21 06:00
MHDA- 2013/02/14 06:00
CRDT- 2012/08/21 06:00
PHST- 2012/08/21 06:00 [entrez]
PHST- 2012/08/21 06:00 [pubmed]
PHST- 2013/02/14 06:00 [medline]
AID - 10.1039/c2an16018h [doi]
PST - ppublish
SO  - Analyst. 2012 Oct 21;137(20):4751-9. doi: 10.1039/c2an16018h.