A Self‐Assembling Tripeptide‐Based Fluorescence Bio‐Nanosensor

Abstract

A de novo tripeptide, YFF, can self‐assemble into fluorescent nanostructures under ultraviolet irradiation, and their fluorescence can be selectively quenched by copper ions. Copper ions can co‐assemble with YFF NPs into hierarchical nanostructures, and the quenched fluorescence can recover again with the addition of pyrophosphate (diphosphate, PPi), which is due to the robust interaction between copper ions and PPi. Based on this principle, a simple and cost‐effective alkaline phosphatase (ALP) biosensor has been built up by making use of the specific dephosphorylation of ALP to PPi, in which the coordinated copper ions can reversibly bind to PPi, thus quench and recover the fluorescence of tripeptide nanostructures. The fluorescence intensity correlated well to the concentration of Cu2+ (2–100 μM), PPi (0–500 μM) and ALP (0–500 U/L) i, respectively, and the corresponding limits of detection (LOD) are 1.29 μM, 0.77 μM and 1.84 U/L, respectively. The designed tripeptide‐based nanosensor also exhibits biocompatible, robust sensing performance in serum, indicating its great potential application for clinical diagnosis.

Fluorescent probes based on the core–shell structure of molecular imprinted materials and gold nanoparticles for highly selective glutathione detection

“…LOD = 3 σ / k , where σ and k are the standard deviation of the residuals and the slope from the calibration curve, respectively. 15,16…”

“…LOD = 3s/k, where s and k are the standard deviation of the residuals and the slope from the calibration curve, respectively. 15,16 Selective experiments 1 mL of R-AuNPs was combined with 0.1 mL of 10 mM GSH, 4-AP, D-penicillamine, cysteine, 2-MP, histidine, proline, GSSG, CuCl 2 , NaCl, KCl, MgCl 2 , CaCl 2 , ZnCl 2 , HgCl 2 , FeCl 2 , FeCl 3 , tyrosine, glucose, ATP, ALP, T 4 PNK, GO x , HSA, HRP, and AchE, respectively. Vortex oscillation was performed for 5 minutes, and the uorescence intensity at 365 nm excitation was measured.…”

“…It is widely used for qualitative or quantitative detection in organisms. 16 AuNPs have high extinction coefficients and are good uorescence quenchants, and they are oen used in the construction of uorescence sensors. AuNPs exhibit potential theoretical and application value in many elds due to their unique stability, small size effect, quantum effect and surface effect.…”