Exploring the use of the tripeptide Gly–Gly–His as a selective recognition element for the fabrication of electrochemical copper sensors

Abstract

The modification of electrodes with the tripeptide Gly-Gly-His for the detection of copper in water samples is described in detail. The tripeptide modified electrode was prepared by first self-assembling 3-mercaptopropionic acid (MPA) onto the gold electrode followed by covalent attachment of the tripeptide to the self-assembled monolayer using carbodiimide coupling. The electrodes were characterized using electrochemistry, a newly developed mass-spectrometry method and quantum mechanical calculations. The mass spectrometry confirmed the modification to proceed as expected with peptide bonds formed between the carboxylic acids of the MPA and the terminal amine of the peptide. Electrochemical measurements indicated that approximately half the MPA molecules in a SAM are modified with the peptide. The peptide modified electrodes exhibited high sensitivity to copper which is attributed to the stable 4N coordinate complex the peptide formed around the metal ion to give copper the preferred tetragonal coordination. The formation of a 4 coordinate complex was predicted using quantum mechanical calculation and confirmed using mass spectrometry. The adsorption of the copper to the peptide modified electrode was consistent with a Langmuir isotherm with a binding constant of (8.1 +/- 0.4) 10(10) M(-1) at 25 degrees C.

Peptide modified SWNT array-based copper sensor

“…The GlyGlyHis tripeptide was found to specifically bind to copper with minimalistic interferences from other metal ions in solution. Ni 2+ ion species showed a slight but noticeable electrochemical response as indicated by previous studies [8]. The reduction peak current however, is negligible in comparison to that obtained with Cu…”

“…Figure 5 shows a CV obtained after incubation of the electrode in a 1nM Cu 2+ solution. Nitrogen atoms from each peptide bond and the imidazole ring form a stable 4N complex with a low binding energy (-816.2kJ/mol) [7]. The GlyGlyHis tripeptide was found to specifically bind to copper with minimalistic interferences from other metal ions in solution.…”

Copper-Binding Peptides from Human Prion Protein and Newly Designed Peroxidative Biocatalysts

“…None of the oligoglycyl peptides lacking histidine (G n ) showed catalytic activity. Within the G n H series (n = 2, 3, 4, 5, and 10), the common minimal motif was G 2 H tripeptide which is known as minimal but active element for binding copper ions (Yang et al, 2003). However, catalytic activity of the minimal Cu-binding motif was hardly detected, but the G 3 H tetrapeptide produced a detectable increase in CLA-CL (Fig.…”

Screening of Peptide Sequences Cognitive of Pb2+by Biopanning

“…환경 위해물질로 존재하는 미량 중금속의 탐지, 분석 혹은 제거와 관련된 문제점들을 해결하는 한 방편으로 특정한 표 적 물질에 선택적 친화력이 높은 리간드 (ligand)가 탐색되어 왔다. 예를 들어 카드뮴, 아연 등의 중금속에 대한 생물학적 리간드들이 보고되었는데 [7][8][9], 이러한 리간드들은 다양한 플랫폼의 바이오센서 인지부 혹은 생흡착제의 반응부위로 서 응용될 수 있다 [10]. 아미노산 올리고머인 펩타이드 역시 대표적인 생물학적 리간드로서 표적 물질에 선택적 친화력 을 보이는 펩타이드 서열들이 알려지고 있다.…”