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Development of electrochemical calcium sensors by using silicon nanowires modified with phosphotyrosine.
Bi, Xinyan; Wong, Wan Ling; Ji, Wenjun; Agarwal, Ajay; Balasubramanian, N; Yang, Kun-Lin.
Afiliação
  • Bi X; Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576, Singapore.
Biosens Bioelectron ; 23(10): 1442-8, 2008 May 15.
Article em En | MEDLINE | ID: mdl-18242974
ABSTRACT
This paper reports the electrical detection of calcium ions by using silicon nanowires (SiNWs) as channels in a chemically gated field-effect-transistor (FET) configuration. To obtain a selective and sensitive layer for calcium sensing, the SiNWs are modified with a biologically relevant amino acid phosphotyrosine (p-Tyr), which is able to complex calcium ions with high affinity. It is found that when the p-Tyr modified SiNWs are exposed to aqueous solutions containing calcium ions, their conductances increase with the increasing of calcium concentration up to 10microM. In contrast, when the SiNWs are exposed to sodium or potassium, or when they are modified with tyrosine (Tyr), no significant increase in the conductance is observed. This finding suggests that the calcium ions complexed with the phosphate group of p-Tyr can act as a positive gate voltage on the FET device comprising of n-type SiNWs, and leads to an increase in their conductances. The FET device is also sensitive to magnesium ions. However, the response is 10 times lower than that of calcium at the same concentration. The study reported here may pave the way for designing an intracellular calcium sensor which permits the monitoring of calcium concentration in real time.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Silício / Cálcio / Fosfotirosina / Nanotecnologia / Nanotubos / Eletroquímica / Microeletrodos Tipo de estudo: Evaluation_studies Idioma: En Ano de publicação: 2008 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Silício / Cálcio / Fosfotirosina / Nanotecnologia / Nanotubos / Eletroquímica / Microeletrodos Tipo de estudo: Evaluation_studies Idioma: En Ano de publicação: 2008 Tipo de documento: Article