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Determination of Cu(II) plays a critical role to prevent over dosage of Cu(II) that exceed cellular needs in drinking water. Rare sensors based on localized surface plasmon resonance (LSPR) are used to determinate the trace of metal ions. In this work, a process of LSPR sensor is developed to determinate Cu(II) with LSPR. A trench array was fabricated via photolithography to wet the bottoms of trenches using oxygen plasma. Hydrophobic halogen-terminated silane, a water immiscible compound before hydrolysis, was evaporated for deposition on the plasma-treated trench template surface. The silane compound was hydrolyzed along the edges of two sides of the trench bottom to form a dual-stripe of an initiator. Polyacrylonitrile (PAN) was grafted from the dual-stripe of the initiator to covert to polyvinyltetrazole (PVT) dual-stripes via a cyano-to-tetrazole reaction, which could chelate Cu(II) at various concentrations. a The Cu(II) ions within the PVT dual-stripes were reduced to form a PVT–copper hybrid dual-stripe nanowires (PCDW) array, resulting in a geometrical change from a dual-stripe to a two-humped structure as the Cu(II) was chelated by the PVT dual-stripes after the in-situ reduction. The reflectance spectra could be used to analyze the position of the extinction wavelength and the peak shape of PCDW array. The linear range between the wavelength shift and Cu(II) concentration from 10 to 1280 nM was established to obtain the detection limit of ∼10 nM. Our proposed method provides a novel pathway to efficiently fabricate a dual-nanowire array with a scale of less than 100 nm, which demonstrates significant potential for highly sensitive and selective Cu(II) sensing. • Scalable dual-stripe arrays of ATRP were formed on a silicon substrate via semiconductor processes. • PAN dual-stripes were grafted from the dual-stripes of the initiator via ATRP as a precursor to convert to PVT dual-stripes. • Cu(II) ions were chelated by PVT dual-stripes to synthesize PVT–copper hybrid dual-stripe nanowires after in-situ reduction. • The reflectance peaks of the PCDW array shift linearly with increasing Cu(II) concentration. • The limit of detection of the platform reaches 10 nM Cu(II) with linear range from 10–1280 nM. [ABSTRACT FROM AUTHOR]

Mixed ligand dinuclear copper(II) complexes of the general formula [Cu2( Rdtc) tpmc)](ClO4)3 with octaazamacrocyclic ligand tpmc and four different heterocyclic dithiocarbamate ligands Rdtc−, as well as the complexes [Cu2( tpmc)](ClO4)4 and [Cu( tpmc)](ClO4)2⋅2H2O were studied in aqueous NaClO4 and HClO4 solutions by cyclic voltammetry on glassy carbon electrode. The electrochemical properties of the ligands and Cu(II) complexes were correlated with their electronic structure. Conductometric experiments showed different stoichiometry in complexation of tpmc with Cu2+ ions and transport of ions in acetonitrile and in aqueous media. These studies clarified the application of this macrocyclic ligand as ionophore in a PVC membrane copper(II) selective electrode and contributed elucidation of its sensor properties. [ABSTRACT FROM AUTHOR]

Here, four nontraditional fluorescent polymers ( NTFP s) of varying N , N -dimethyl-2-propenamide (DMPA) and butyl prop-2-enoate (BPE) mole ratios, i.e., 2:1 ( NTFP1 ), 4:1 ( NTFP2 ), 8:1 ( NTFP3 ), and 16:1 ( NTFP4 ), are prepared via random polymerization in water. The maximum fluorescence enhancement of NTFP3 makes it suitable for ratiometric pH sensing, Cu(II) sensing, and pH-dependent cell imaging of Madin-Darby canine kidney (MDCK) cells. The oxygen donor functionalities of NTFP3 involved in binding and sensing with Cu(II) ions are studied by absorption, emission, electron paramagnetic resonance, Fourier transform infrared (FTIR), and O1s/Cu2p X-ray photoelectron spectroscopies (XPS). The spectral responses of the ratiometric pH sensor within 1.5-11.5 confirm 22 and 44 nm red shifts in absorption and ratiometric emission, respectively. The striking color changes from blue (436 nm) to green (480 nm) via an increase in pH are thought to be the stabilization of the charged canonical form of tertiary amide, i.e., -C(O - )═N + (CH 3 ) 2 , realized from the changes in the absorption/fluorescence spectra and XPS/FTIR analyses. The through-space n -π* interactions in the NTFP3 aggregate, N-branching-associated rigidity, and nonconventional intramolecular hydrogen bondings of adjacent NTFP3 moieties in the NTFP3 aggregate contribute to aggregation-enhanced emissions (AEEs). Here, structures of NTFP3 , NTFP3 aggregate, and Cu(II)- NTFP3 ; absorption; n -π* interactions; hydrogen bondings; AEEs; and binding with Cu(II) are ascertained by density functional theory, time-dependent density functional theory, and reduced density gradient calculations. The excellent limits of detection and Stern-Volmer constants of NTFP3 are 2.24 nM/0.14234 ppb and 4.26 × 10 3 M -1 at pH = 6.5 and 0.95 nM/0.06037 ppb and 4.90 × 10 3 M -1 at pH = 8.0, respectively. Additionally, the Stokes shift and binding energy of NTFP3 are 13,636 cm -1 /1.69 eV and -4.64 eV, respectively. The pH-dependent MDCK cell imaging ability of noncytotoxic NTFP3 is supported via fluorescence imaging and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.