Optical monitoring of micro fluidic flow conditions, employing surface plasmon resonance sensing

Effect of alkanethiol molecular structure on sensitivity of surface plasmon resonance sensor

“…If we further consider that the -30% error due to the double layer charging current could be reflected in the surface concentrations calculated from the total reductive desorption charge, these concentrations are comparable to the result found from the angle shift of SPR and STM image calculations (with the assumption that each molecule of DSU, CEG 6 , and C 2 -NTA occupied 0.3, 0.27, and 0.6 nm 2 , respectively; Fig. S1 in Supporting Information), as summarized in Table 1.…”

“…The surface concentrations of the DSU, CEG 6 , and C 2 -NTA (were calculated using equation mentioned in Supporting Information, and were already corrected by the roughness factor of 1.50) thiols were 6.6 × 10 -10 , 8.5 × 10 -10 and 4.6 × 10 -10 mol cm -2 , respectively. If we further consider that the -30% error due to the double layer charging current could be reflected in the surface concentrations calculated from the total reductive desorption charge, these concentrations are comparable to the result found from the angle shift of SPR and STM image calculations (with the assumption that each molecule of DSU, CEG 6 , and C 2 -NTA occupied 0.3, 0.27, and 0.6 nm 2 , respectively; Fig.…”

“…It was noticed that the monolayer structure determined the immunoassay sensitivity due to the orientation and the surface concentration of antigen in domain structure of monolayer. To study the effect of orientation of antigen, we examined here three types of alkanethiol compounds: dithiobis(succinimidyl undecanoate) (DSU; straight-chain alkanethiol), carboxy-EG 6 mol cm -2 , respectively. Subsequently, SPR suggested that the ratios of immobilized antigen (clenbuterol) per thiol were 0.13, 0.16, and 0.15 for DSU, CEG 6 , and C 2 -NTA, respectively.…”

“…To study the effect of orientation of antigen, we examined here three types of alkanethiol compounds: dithiobis(succinimidyl undecanoate) (DSU; straight-chain alkanethiol), carboxy-EG 6 mol cm -2 , respectively. Subsequently, SPR suggested that the ratios of immobilized antigen (clenbuterol) per thiol were 0.13, 0.16, and 0.15 for DSU, CEG 6 , and C 2 -NTA, respectively. This suggests that the amount of immobilized clenbuterol was defined by the molecular size of clenbuterol.…”

“…Several developments in biosensors have been reported, such as fluidic design [5][6][7], sensor surface immobilization [8][9][10][11], advances in detection methods [12][13][14][15], and data analysis [15][16]. An ideal biosensor is reliable, selective, sensitive, quick to respond, and inexpensive to fabricate.…”