TY - JOUR
T1 - Surface characterization and platelet adhesion studies of self-assembled monolayer with phosphonate ester and phosphonic acid functionalities
AU - Tsai, Meng Yen
AU - Lin, Jui Che
PY - 2001/6/15
Y1 - 2001/6/15
N2 - Because of its well-defined surface configuration and creative chemical structure, an alkanethiol self-assembled monolayer (SAM) on gold is a model surface for a blood compatibility investigation. In this study two laboratory-synthesized long-chain alkanethiols, HS(CH2)10PO3-(C2H5) 2 and HS(CH2)10PO3H2, were employed for the direct preparation of SAMs with nonionic and ionic functional groups. Various instrumental analyses confirmed the high purity of the phosphonate ester and phosphonic acid terminated alkanethiols. The surface characterization results showed the -PO3H2 terminated SAM was more hydrophilic than the -PO3(C2H5)2 one. Higher hysteresis values for the -PO3(C2H5)2 and -PO3H2 terminated SAMs were noted, which were possibly due to the steric hindrance of the bulky terminal groups. In addition, the O2 plasma + EtOH-rinse pretreated Au sample was hydrophilic because of the residual gold oxide on the surface. This finding was supported by electron spectroscopy for chemical analysis (ESCA) as well. The ESCA analysis also indicated bulky and polar terminal groups [-PO3(C2H5)2 and -PO3H2] were situated in the outermost layer of its monolayer. The platelet reactivity on the SAM with the nonionic group -PO3(C2H5)2 was less than those of the ionic terminated SAMs -COOH and -PO3H2. The O2 plasma + EtOH-rinse pretreated gold substrate exhibited the least platelet-activating surface among the different pretreated Au substrates studied.
AB - Because of its well-defined surface configuration and creative chemical structure, an alkanethiol self-assembled monolayer (SAM) on gold is a model surface for a blood compatibility investigation. In this study two laboratory-synthesized long-chain alkanethiols, HS(CH2)10PO3-(C2H5) 2 and HS(CH2)10PO3H2, were employed for the direct preparation of SAMs with nonionic and ionic functional groups. Various instrumental analyses confirmed the high purity of the phosphonate ester and phosphonic acid terminated alkanethiols. The surface characterization results showed the -PO3H2 terminated SAM was more hydrophilic than the -PO3(C2H5)2 one. Higher hysteresis values for the -PO3(C2H5)2 and -PO3H2 terminated SAMs were noted, which were possibly due to the steric hindrance of the bulky terminal groups. In addition, the O2 plasma + EtOH-rinse pretreated Au sample was hydrophilic because of the residual gold oxide on the surface. This finding was supported by electron spectroscopy for chemical analysis (ESCA) as well. The ESCA analysis also indicated bulky and polar terminal groups [-PO3(C2H5)2 and -PO3H2] were situated in the outermost layer of its monolayer. The platelet reactivity on the SAM with the nonionic group -PO3(C2H5)2 was less than those of the ionic terminated SAMs -COOH and -PO3H2. The O2 plasma + EtOH-rinse pretreated gold substrate exhibited the least platelet-activating surface among the different pretreated Au substrates studied.
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U2 - 10.1002/1097-4636(20010615)55:4<554::AID-JBM1049>3.0.CO;2-V
DO - 10.1002/1097-4636(20010615)55:4<554::AID-JBM1049>3.0.CO;2-V
M3 - Article
C2 - 11288084
AN - SCOPUS:0035877422
VL - 55
SP - 554
EP - 565
JO - Journal of Biomedical Materials Research
JF - Journal of Biomedical Materials Research
SN - 1552-4973
IS - 4
ER -