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Background: Apolipoprotein AI (ApoAI) and ApoB are risk indicators of cardiovascular disease. We describe the use of immunoresonance scattering to measure the ApoAI and ApoB in serum., Methods: We used a trisodium citrate method to prepare 9.0-nm gold nanoparticles labeled with goat anti-human ApoAI and ApoB antibodies. The immune reaction between gold-labeled antibodies and antigens took place in Na2HPO4-NaH2PO4 buffer solution (pH 6.4 for ApoAI and pH 6.0 for ApoB) in the presence of 75 g/L polyethylene glycol (PEG). We used a transmission electron microscope to observe the shape of the gold nanoparticles. Results were compared with those obtained by immunoturbidimetric methods. Twenty-five human serum samples were assayed by the immunoresonance scattering assay preset with the data indicated and by an immunoturbidimetric assay., Results: The presence of PEG greatly enhanced the intensity of resonance-scattering peaks at 560 nm. The intensity (DeltaI) was proportional to concentration at 0.00833-0.3333 mg/L ApoAI and 0.00197-0.1972 mg/L ApoB. The detection limits were 2.04 and 0.96 microg/L for ApoAI and ApoB, respectively. The results for human serum samples were in agreement with those obtained with an immunoturbidimetric method. Linear regression analysis revealed a correlation coefficient, slope, and intercept of 0.915, 0.966, and 68.53 mg/L, respectively, for ApoAI and 0.919, 0.996, and 15.46 mg/L for ApoB., Conclusion: This method showed high sensitivity and good selectivity for quantitative determination of ApoAI and ApoB in human serum, with satisfactory results.

In a suitable pH buffer solutions, sodium diethyldithiocarbamate (DDTC) reacts with some divalence metal ions M(II) to form (M-DDTC)( n ) chelate complex nanoparticles, which exhibit different luminescence properties. There is a strongest luminescence peak at 470 nm for the Co(II)-DDTC system, three peaks at 330, 470, and 630 nm for the Cu(II)-DDTC system, three peaks at 420, 470, and 630 nm for the Cd(II)-DDTC system, four peaks at 350, 400, 435, and 470 nm for the Ni(II)-DDTC system, two peaks at 408 and 470 nm for the Pb(II)-DDTC system, two peaks at 415 and 470 nm for the Fe(II)-DDTC system. The different luminescence properties of (M-DDTC)( n ) chelate complex nanoparticles was explained. Under the optimal conditions, the luminescence intensity of (Co-DDTC)( n ) chelate complex nanoparticles at 470 nm (F (470 nm)) is linear to Co(II) concentration in the range of 0.012-1.44 microg/mL. The detection limit is 0.0023 microg/mL. A novel luminescence method has been proposed for the determination of cobalt in Vitamin B(12) samples, with satisfactory results.

Yellow silver nanoparticles in water phase were prepared by microwave synthesis method. Study found that there is a fluorescence peak at 465 nm and a strongest resonance scattering peak at 460 nm for the nanoparticles. The resonance scattering intensity at 465 nm I(460 nm). fluorescence intensity at 465 nm F(465)(nm) and absorbance at 455 nm A(455 nm) were found linear to the concentration c(Ag) in the range from 0 to 3.5x10(-4)mol/L Ag, with linear regression equation for I(460 nm)=48.1x10(4) c(Ag)+3.69 and F(465 nm)=28.7x10(4)c(Ag)+3.50 and A(455 nm)1.23x10(4)c(Ag)+0.01, their regression coefficient for 0.9976, 0.9954 and 0.9957, respectively. When the c(Ag) was over 3.5x10(-4)mol/L, the resonance scattering peak and fluorescence peak of 465 nm take place red-shift and display luminescence quenching, but the absorption peak place does not change and the absorption intensity enhances. The paper reports the spectral properties of silver nanoparticles in water phase, and offers the principle of interface luminescence electron to state the luminescence effect of silver nanoparticles.

There is a fluorescence peak at 570 nm, and a maximum absorption peak at 560 nm for phloxine (PHLO) in a pH 7 water solution. Under these conditions, the ciprofloxacin cation (CPFX+) and PHLO- combine into hydrophobic CPFX-PHLO association molecule by means of static gravitation. There are stronger van der Waals forces and hydrophobic forces among the CPFX-PHLO molecules. Thus, they aggregate automatically to the (CPFX-PHLO)n association nanoparticle in red-violet color. That was characterized by scan electron microscopy (SEM), hyperfiltration and dialysis tests. In 0.04 M HCl, the red-violet nanoparticles exhibited a Rayleigh scattering peak at 470 nm, a resonance scattering peak at 580 nm, a maximum absorption wavelength at 565 nm, and a fluorescence peak at 450 nm. The fluorescence analytical conditions of CPFX have been considered. The CPFX concentration in the range of 1.0 x 10(-6)-4.0 x 10(-5) M is linear to the fluorescence intensity, F450nm. The detection limit was achieved at 4.0 x 10(-7) M CPFX. The CPFX in real samples was determined with satisfactory results.

The Ag cluster in solution has been prepared by a microwave high-pressure procedure. There is a maximum resonance Rayleigh scattering (RRS) peak at 425 nm (7.06 x 10(14) Hz) and a smaller RRS peak at 850 nm (1/2 x 7.06 x 10(14) Hz) by synchronous scattering at lambda(ex) = lambda(em). It is a nonlinear optical medium. When scattering the emission wavelength (lambda(em)) as the excited wavelength (lambda(ex)) at 425 nm (7.06 x 10(14) Hz), a maximum RRS peak was observed at 425 nm (7.06 x 10(14) Hz). A 1/2 fraction scattering peak at 850 nm (1/2 x 7.06 x 10(14) Hz) was also investigated. When lambda(ex) is at 850 nm (3.53 x 10(14) Hz), a frequency-doubling scattering peak at 425 nm is observed, and a RRS peak is displayed at 850 nm (3.53 x 10(14) Hz). When the lambda(ex) is two times longer than the maximum RRS wavelength (the strongest wavelength of pump band lambda(pb)) of an atomic cluster, a nonlinear scattering frequency-doubling peak (lambda(pb)) exhibits at half of the lambda(ex), which is stronger than the RRS peak. This phenomenon is defined as pump effect.

A novel resonance scattering spectral method has been proposed for the determination of trace amounts of chlorides in the range of 2 x 10(-7)-8 x 10(-6) mol/l. It was based on the photochemical reaction system of AgNO3-NaCl-sodium oxalic to form the (AgCl)nucleus (n)(Ag)shell (s) nanoparticle. There is a strongest resonance scattering peak at 470 nm and a maximum absorption peak at 425 nm. The concentration of chlorides is proportional to the intensity of resonance scattering at 470 nm. The nonlinear resonance scattering peaks of the nanoparticle system have been also considered, according to the theory of the interaction between the surface electron of nanoparticle and the incidence photon.