Dual-Signal Luminescent Detection of Dopamine by a Single Type of Lanthanide-Doped Nanoparticles

Abstract

Detection of dopamine, an important neurotransmitter, is vital for understanding its roles in mammals and disease diagnosis. However, commonly available methods for dopamine detection typically rely on a single signal readout, which can be susceptible to interference by internal or external factors. Here, we report a dual-signal detection of dopamine based on label-free luminescent NaGdF:Tb nanoparticles. In the presence of dopamine, the NaGdF:Tb nanoparticles exhibit luminescence quenching under the excitation of 272 nm, while they give enhanced luminescence under 297 nm excitation, realizing both turn off and turn on detection of dopamine. The nanoparticle-based dual-signal sensors exhibit high sensitivity, with a detection limit of ∼30 nM, and good selectivity, which offers the possibility to identify potential interferents in the samples. We further demonstrate that the dual-signal response results from different energy-transfer processes within the nanoparticles under the excitation of different light. The new strategy demonstrated here should pave the way for the development of multiresponse nanosensors based on lanthanide-doped luminescent nanomaterials.

Coating and Transforming the Y(OH)CO₃ Shell on Upconversion Nanoparticles

“…Considering that Y(OH)CO3 was typically synthesized in aqueous solutions, we then removed the oleic acid ligand on NaGdF4:Yb/Tm nanoparticles by thorough acid treatment in order to make the nanoparticles hydrophilic 41 . TEM image (Fig.…”

“…Although the size of the nanoparticles became slightly smaller after acid treatment (Fig. S2c) because of acid etching 41 , the resulting ligand-free NaGdF4:Yb/Tm nanoparticles maintained their crystallinity and crystal structure (Fig. S2b and d).…”

“…Urea (H2NCONH2, AR) and all other chemicals (AR grade) were obtained from Sinopharm Chemical Reagent Beijing Co., Ltd. All the chemicals were used as received unless otherwise noted. 2.2 Synthesis of NaGdF4:Yb/Tm@Y(OH)CO3 coreshell nanoparticles NaGdF4:Yb/Tm (49/1 mol%, mole fraction) upconversion nanoparticles were first synthesized according to previous reports 41 . Briefly, to a two-neck round-bottom flask, oleic acid (4 mL) and an aqueous solution (2 mL) containing Gd(CH3COO)3 (0.2 mmol), Yb(CH3COO)3 (0.196 mmol), and Tm(CH3COO)3 (0.004 mmol) were added, and the resulting mixture was stirred (300 r•min −1 ) at 130 °C for 30 min.…”

“…The oleic acid ligands, on the surface of NaGdF4:Yb/Tm nanoparticles, were then removed by HCl treatment 41 . Typically, the obtained NaGdF4:Yb/Tm nanoparticles in cyclohexane (1 mL) were first collected by the addition of ethanol (0.8 mL) and centrifugation (16000 r•min −1 , 5 min).…”

Upconversion luminescence in cellulose composites (fibres and paper) modified with lanthanide-doped SrF2 nanoparticles

“…[1][2][3][4][5] Currently, interest in the formation of lanthanidedoped nanomaterials is growing, almost exponentially. [6][7][8][9][10] This is mainly due to their favourable optical, electronic, magnetic, and catalytic properties. [10][11][12][13] Inorganic materials doped with Ln 3+ ions usually exhibit resistance to photobleaching, high-temperature and high-pressure treatment, stability of the 3+ oxidation state, and low cytotoxicity, etc.…”