Peak photocurrent density (nA/cm2)

2.5 3.5 4.5 5.5 5.75 6 6.5 7.5 8.5 9.5 10.5 11.5

-20 -15 -10 -5 0 5 10 15 20

P e a k p h o to c u rr e n t d e n s it y ( n A /c m

)

pH value

light-on light-off

Fig. 5-104 pH effects of electrolytes on the peak photocurrent densities of photoelectric native PM chips coated with the EC side toward ITO. Green columns represent the photocurrent densities of the Xenon light-on signals. Red columns represent the photocurrent densities of Xenon light-off signals. Ranges indicate the standard deviations of the results using three chips.

3.5 4.5 5.5 5.75 6 6.5 7.5 8.5 9.5 10.5 11.5

-15 -10 -5 0 5 10 15 20 25 30 35 40

P h o to c u rr e n t d e n s it y ( n A /c m

)

pH value

Fig. 5-105 pH effects of electrolytes on the photocurrent densities of photoelectric native PM chips coated with the EC side toward ITO. The values represent the total photocurrent densities (Xenon light-on signals minus the light-off signals). Ranges indicate the standard deviations of the results using three chips.

Fig. 5-106 The proton translocation sequence of native PM in (a) low-pH and (b) high-pH electrolytes.

δ⁺

δ⁺ δ^－－－－

δ^－－－－

(a)

pH ≦ ≦ ≦ ≦ 5.75

pH ≧ ≧ ≧ 5.75 ≧

5-6-3-3 電解液中添加物對

對於 D96N BR 突變種，由於其 Asp96 殘基被 Asn 胺基酸取代的結果會導致 BR 之 M 態光學中間體的生命週期被延長，而使得質子無法被正常由膜外傳送進入膜內，預期 會對其單層定向膜晶片的光電流訊號同時產生影響。所以研究中我們量測其定向膜晶片 的光電流訊號，並嘗試在電解液中加入帶正電性最強的胺基酸：lysine，改變電解質環 境，以期降低突變對光電流訊號的影響。同理，我們也加入 NaN3（sodium azide），探討 其添加效益。

由 Fig. 5-107、Fig. 5-108、Fig. 5-109 結果觀察，加入 lysine 對 peak off 的改變並不 大，只是將 peak on 的訊號降低成和 peak off 差不多。所以我們可以知道加入 lysine 對 peak off 的訊號並不會造成上升，反而導致 peak on 和 peak off 訊號皆下降。可能是因為 電解液中的陰離子未移動至電極處，反而與 lysine 結合在一起，造成測得的光電流降低。

反之，由 Fig. 5-110、Fig. 5-111、Fig. 5-112 的結果可知，添加 NaN₃的效果可說是十分 顯著。但隨著濃度增加到約 20 mM 後，再增加 NaN₃的濃度其效果便隨之下降。但 peak on 和 peak off 的訊號並不會同時增減。所以選擇 peak on 和 peak off 的訊號相差不會太 大，且 peak on 減 peak off 有最大值的濃度才是最好的！因此就此結果而言，NaN3濃度 在 10 mM 至 20 mM 對 D96N PM 定向單層膜晶片的光電流具有最佳的添加效益。

(a) 0 mM lysine filter rise time = 100 (msec)

(c) 1 mM lysine filter rise time = 100 (msec)

(d) 3 mM lysine filter rise time = 100 (msec)

(e) 5 mM lysine filter rise time = 100 (msec)

(f) 10 mM lysine filter rise time = 100 (msec)

(g) 30 mM lysine

IT O /NH /GA/S Av/biotin-D96N PM filter rise tim e = 100 (m sec) filter rise time = 100 (msec)

(i) 70 mM lysine

IT O/N H /GA/SAv/biotin--D 96N PM filter rise tim e = 100 (m sec)

0 10 20 30 40 50 60

Current (nA)

Lysine (mM)

peak on - peak off

0 0.5 1 3 5 10 30 50 70 100

Fig. 5-109 Lysine 的添加對 D96N 晶片 peak on- peak off 訊號的影響

(a) 0 mM NaN₃ filter rise time = 100 (msec)

(b) 1 mM NaN3 filter rise time = 100 (msec)

(c) 3 mM NaN₃ filter rise time = 100 (msec)

(d) 5 mM NaN₃ filter rise time = 100 (msec)

(e) 10 mM NaN₃ filter rise time = 100 (msec)

(f) 20 mM NaN₃ filter rise time = 100 (msec)

(g) 30 mM NaN₃ filter rise time = 100 (msec)

(h) 70 mM NaN₃ filter rise time = 100 (msec)

Fig. 5-110 NaN₃的添加對 D96N PM 定向單層膜晶片光電流訊號的影響

0 10 20 30 40 50 60 70 0

10 20 30 40 50 60

Current (nA)

NaN₃ (mM)

peak on peak off

Fig. 5-111 NaN₃添加對 D96NPM 定向單層膜晶片 peak on 與 peak off 訊號之影響

0 5 10 15 20 25 30 35

NaN3 (mM)

Current (nA)

peak on - peak off

0 1 3 5 10 20 30 70

Fig. 5-112 NaN3添加對 D96N 定向單層膜晶片整體光電流的影響

第

D96N、D85N/D96N 與 G241C 突變膜蛋白之 H. salinarum 菌株。對於各突變蛋白進行探 討，發現突變對 BR 的光譜、菌體與 PM 膜的顏色外觀和其產量以及對其光電流響應均