TY - JOUR
T1 - Double probe approach to protein adsorption on porous carbon surfaces
AU - Nagy, Balázs
AU - Tóth, Ajna
AU - Savina, Irina
AU - Mikhalovsky, Sergey
AU - Mikhalovska, Lyuba
AU - Geissler, Erik
AU - László, Krisztina
N1 - Funding Information:
Financial support from the Marie Curie International Research Staff Exchange Scheme (ENSOR, Grant No. 269267 ), the Marie Curie Reintegration grant, PERG08-GA-2010-276954, and OTKA K109558 is acknowledged. AT recognizes the support of TÁMOP 4.2.4. A/1-11-1-2012-0001 “National Excellence Program – Elaborating and operating an inland student and researcher personal support system”. The project was subsidized by the European Union and co-financed by the European Social Fund.
PY - 2017/2/1
Y1 - 2017/2/1
N2 - Comparison of nitrogen adsorption isotherms of porous carbons before and after exposure to proteins yields information on the pore landscape that is unobtainable from small angle neutron scattering (SANS) [Carbon 2016; 106:142–151]. Two globular proteins, bovine serum albumin (BSA), and bovine pancreatic trypsin inhibitor (BPTI), are studied, with two different porous carbon substrates: a hydrophobic open structured carbon aerogel with basic surface pH (C1), and a hydrophilic medical grade microporous carbon with neutral surface pH (C2). BSA and BPTI both interact more strongly with the hydrophilic carbon than with C1, but C2 adsorbs notably less protein. Both proteins are arrested at the micropore entrances. With increasing concentration in C1, these protein barriers, on drying, seal the micropores hermetically to nitrogen gas. Owing to the adsorbed protein, macropores that are otherwise too wide to be detected in virgin C1 shrink and become detectable by gas adsorption. In C2 the dry protein barriers are looser and remain permeable to nitrogen molecules, leaving the measured micropore and mesopore surface areas practically unaffected. This double probe approach corroborates and extends the earlier SANS findings, highlighting the role played by pore structure and the hydrophilic/hydrophobic character of the substrate in protein adsorption.
AB - Comparison of nitrogen adsorption isotherms of porous carbons before and after exposure to proteins yields information on the pore landscape that is unobtainable from small angle neutron scattering (SANS) [Carbon 2016; 106:142–151]. Two globular proteins, bovine serum albumin (BSA), and bovine pancreatic trypsin inhibitor (BPTI), are studied, with two different porous carbon substrates: a hydrophobic open structured carbon aerogel with basic surface pH (C1), and a hydrophilic medical grade microporous carbon with neutral surface pH (C2). BSA and BPTI both interact more strongly with the hydrophilic carbon than with C1, but C2 adsorbs notably less protein. Both proteins are arrested at the micropore entrances. With increasing concentration in C1, these protein barriers, on drying, seal the micropores hermetically to nitrogen gas. Owing to the adsorbed protein, macropores that are otherwise too wide to be detected in virgin C1 shrink and become detectable by gas adsorption. In C2 the dry protein barriers are looser and remain permeable to nitrogen molecules, leaving the measured micropore and mesopore surface areas practically unaffected. This double probe approach corroborates and extends the earlier SANS findings, highlighting the role played by pore structure and the hydrophilic/hydrophobic character of the substrate in protein adsorption.
KW - Adsorption
KW - BPTI
KW - BSA
KW - Carbon aerogel
KW - Porosity
KW - Protein
KW - Surface chemistry
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U2 - 10.1016/j.carbon.2016.10.095
DO - 10.1016/j.carbon.2016.10.095
M3 - Article
AN - SCOPUS:84994544551
VL - 112
SP - 103
EP - 110
JO - Carbon
JF - Carbon
SN - 0008-6223
ER -