利用矽奈米線場效應電晶體開發以嗜中性白血球明膠酶相關運載蛋白為指標的急性腎臟損傷快速診斷晶片

Abstract

Acute kidney injury (AKI) is condition of rapid or abrupt decline in renal function. Overall, the mortality of AKI is 20%. Serum creatinine and urine output are used to define the prognosis of AKI. However, both indicators are not fast enough to detect AKI. Increase of serum creatinine occurred within 1 to 3 days after AKI; and it is estimated that greater than 50% of kidney function must be lost before serum creatinine rises. Consequently, serum creatinine does not reflect the true decrease of glomerular filtration rate in the acute setting. On the other hand, indicators such as neutrophil gelatinase-associated lipocalin (NGAL) and liver-type fatty acid binding protein increased at an early stage. Generally, the average area under the receiver-operating characteristic curve (AUC-ROC) of predicting AKI by NGAL was 0.79; and NGAL level arises and achieves their peak level arises within four hours after surgeries[1]. Conventional enzyme-linked immunosorbent assay (ELISA) is time-consuming. In order to perform real-time detection of AKI, we developed a fast-detecting biochip using silicon nanowire field-effect transistor (SiNW FET) which can reduce the detection time to less than 30 minutes. In this study, we first successfully purified NGAL recombinant protein and well established NGAL ELISA, which was used as a standard method to compare with. Next, we determined the coating protocol and fIn this study, we first successfully purified NGAL recombinant protein and well established NGAL ELISA, which was used as a standard method to compare with. Next, we determined the coating protocol and found that in the hydroxylation process, cholic acid had the best performance in r square and drifting rate among H2O2, cholic acid and NaOH. In the silanization process, we found that AEAPTES was less prone to self-react than APTES, which was commonly used beforeound that in the hydroxylation process, cholic acid had the best performance in r square and drifting rate among H2O2, cholic acid and NaOH. In the silanization process, we found that AEAPTES was less prone to self-react than APTES, which was commonly used before. By observing and measuring the current change, we could know the protein level within 30 minutes. In this study, 7 AKI and 5 non-AKI samples were quantified. NGAL levels of AKI patients quantified by this system ranged from 1500 to 4000 ng/mL, while levels of four non-AKI samples were 0 ng/mL. By using the SiNW-FET system, AKI and non-AKI samples can be discriminated significantly (p value<0.001). In conclusion, we developed a fast detecting biochip that can be applied to clinical quantification which is able to discriminate AKI and non-AKI samples.