Exploring the impact of hydrogen sulfide on hematologic malignancies: A review.

Hydrogen sulfide (H2S) is one of the three most crucial gaseous messengers in the body. The discovery of H2S donors, coupled with its endogenous synthesis capability, has sparked hope for the treatment of hematologic malignancies. In the last decade, the investigation into the impact of H2S has expanded, particularly within the fields of cardiovascular function, inflammation, infection, and neuromodulation. Hematologic malignancies refer to a diverse group of cancers originating from abnormal proliferation and differentiation of blood-forming cells, including leukemia, lymphoma, and myeloma. In this review, we delve deeply into the complex interrelation between H2S and hematologic malignancies. In addition, we comprehensively elucidate the intricate molecular mechanisms by which both H2S and its donors intricately modulate the progression of tumor growth. Furthermore, we systematically examine their impact on pivotal aspects, encompassing the proliferation, invasion, and migration capacities of hematologic malignancies. Therefore, this review may contribute novel insights to our understanding of the prospective therapeutic significance of H2S and its donors within the realm of hematologic malignancies.

Hydrogen sulfide and its donors: Novel antitumor and antimetastatic agents for liver cancer.

Hepatocellular carcinoma (HCC) is the sixth most frequent human cancer and the world's third most significant cause of cancer mortality. HCC treatment has recently improved, but its mortality continues to increase worldwide due to its extremely complicated and heterogeneous genetic abnormalities. After nitric oxide (NO) and carbon monoxide (CO), the third gas signaling molecule discovered is hydrogen sulfide (H2S), which has long been thought to be a toxic gas. However, numerous studies have proven that H2S plays many pathophysiological roles in mammals. Endogenous or exogenous H2S can decrease cell proliferation, promote apoptosis, block cell cycle, invasion and migration through various cellular signaling pathways. This review analyzes and discusses the recent literature on the function and molecular mechanism of H2S and H2S donors in HCC, so as to provide convenience for the scientific research and clinical application of H2S in the treatment of liver cancer.

The Role of Hydrogen Sulfide in the Development and Progression of Lung Cancer.

Lung cancer is one of the 10 most common cancers in the world, which seriously affects the normal life and health of patients. According to the investigation report, the 3-year survival rate of patients with lung cancer is less than 20%. Heredity, the environment, and long-term smoking or secondhand smoke greatly promote the development and progress of the disease. The mechanisms of action of the occurrence and development of lung cancer have not been fully clarified. As a new type of gas signal molecule, hydrogen sulfide (H2S) has received great attention for its physiological and pathological roles in mammalian cells. It has been found that H2S is widely involved in the regulation of the respiratory system and digestive system, and plays an important role in the occurrence and development of lung cancer. H2S has the characteristics of dissolving in water and passing through the cell membrane, and is widely expressed in body tissues, which determines the possibility of its participation in the occurrence of lung cancer. Both endogenous and exogenous H2S may be involved in the inhibition of lung cancer cells by regulating mitochondrial energy metabolism, mitochondrial DNA integrity, and phosphoinositide 3-kinase/protein kinase B co-pathway hypoxia-inducible factor-1α (HIF-1α). This article reviews and discusses the molecular mechanism of H2S in the development of lung cancer, and provides novel insights for the prevention and targeted therapy of lung cancer.

A new and facile nanosilver SPR colored method for ultratrace arsenic based on aptamer regulation of Au-doped carbon dot catalytic amplification.

Here, Au-doped carbon dots (CDAu) nanosols with good stability were prepared by hydrothermal reaction method. We found that CDAu can efficiently catalyze the nanoreaction of reducing AgNO3 by glucose, and at 420 nm，the reaction products of yellow spherical silver nanosol exhibit an intense surface plasmon resonance (SPR) absorption peak. The nucleic acid aptamers (Apt) can be adsorbed on the surface of carbon dots, so that their catalytic activity was suppressed, the nanosilvers were reduced, the solution color becomes lighter, and the Abs value was weakened. When As3+ was added, it forms a stable conjugate with the Apt, releases free carbon dots, restored its catalytic activity, and the color and Abs signals enhanced linearly. Based on the Apt regulation and the catalytic amplification effect of CDAu on AgNO3-glucose, a new extremely sensitive SPR spectrophotometric method for the determination of arsenic ion content of 0.025-0.75 µg/L was established, and the detection limit of As3+ is 0.01 µg/L.

[A Facile Nanogold Surface Plasmon Resonance Absorption Method for CO Tracing].

The detection of gas pollutants in atmosphere and indoor air is very important to human health and safety. Monoxide carbon (CO) is a common gas pollutant with high toxicity that mainly comes from the inadequacy oxidization of carbon such as oil, coal and petrol inadequacy combustion, auto-gas and some natural disasters whose limit value in air is lower than 6.0 mg·m-3 in the national standard. Due to its toxicity and uneasy detection, it is one of very dangerous component in the silent killer. Recently, several methods, including infra-red absorption, gas chromatography, potentiometry, Hg replacement, spectrophotometry, I2O5 and PdCl2 nake-eye, semiconductor sensor have been reportedly used for the detection of CO. To our best knowledge, there are no SPR absorption methods for CO, based on the NG SPR absorption. In this paper, the reaction between CO and HAuCl4 was studied with absorption spectrophotometry and transmission electron microscopy (TEM)while a simple and rapid SPR absorption method was developed for the determination of trace CO. In pH 7.2 phosphate buffer solutions, monoxide carbon reduced HAuCl4 to form nanogold (NG) particles with the size of about 45 nm that exhibited surface plasmon resonance (SPR) absorption peak at 540 nm and three energy spectral peaks at 1.70 keV, 2.20 and 9.70 keV for gold element. The analytical conditions were examined, and a pH 7.2 phosphate buffer solution with a concentration of 40 mmoL·L-1 PO3-4, a concentration of 40.0 µg· mL-1 HAuCl4 and a reaction time of 5 min was selected for use. Under the selected conditions, the SPR absorption peak value was linear to CO concentration in the range of 0.2～8.75 µg· mL-1, with a detection limit of 0.1 µg· mL-1 CO. According to the procedure, the influence of coexistent substances on the determination of 1.0 mg·L-1 CO was tested, with a relative error of ±5%. Results indicated that 200 times SO2-3, PO3-4, SO2-4, CO2-3 and NO-3, 100 times Zn2+, K+, BrO-3, Na2S, ethanol, methanol, 80 times Ni2+, Cr3+, Co2+, Ca2+, Mg2+, Fe3+, glucose, Pb2+, Al3+, SeO2-3, Na2S2O3, formaldehyde, 50 times Mn2+ do not interfere with the determination. It showed that this SPR method had good selectivity. The CO content in air samples was determined with the SPR method, with a relative standard deviation (RSD) of 1.8%～4.2%, the SPR method results were agreement with that of the gas chromatography (GC).

[A Hydride Generation-Catalytic Resonance Rayleigh Scattering Method for Detection of Trace Arsenic].

Arsenic is a toxic metal element and the establishment of a highly sensitive and selective method for As has great significance to human health and environment protection. In sulfuric acid medium, As(Ⅲ) was reduced by NaBH4 to form AsH3 gas that was trapped by the Ce(Ⅳ)-I- catalytic absorption solution to cause Ce(Ⅳ) concentration decreased and As particle increased, which resulted in the resonance Rayleigh scattering (RRS) and fluorescence increased at 370 and 351 nm respectively. The increased RRS and fluorescence intensities were linear to As(Ⅲ) concentration in the range of 0.006~0.76 and 0.006~0.28 mg·L(-1) respectively, with a detection of As of 3.0 µg·L(-1). The new hydride generation-catalytic RRS method was applied for detection of trace As(Ⅲ) in milk samples, and the results were in agreement with that of hydride generation-atomic absorption spectrometry.

[Determination of Trace Boron Based on Gold Nanorod Plasmonic Resonance Rayleigh Scattering Energy Transfer to the Coordinate].

B is a necessary trace element for human and animals, but the excess intake of B caused poison. Thus, it is very important to determination of B in foods and water. The target of this study is development of a new, sensitive and selective resonance Rayleigh scattering energy transfer (RRS-ET) for the determination of B. The combination of energy transfer with resonance Rayleigh scattering (RRS) has developed a new technology called RRS-ET, which can realize selective and sensitive detection of boric acid. The gold nanorods in diameter of 12 nm and length of 37 nm were prepared by the seed growth procedure. In pH 5. 6 NH4 Ac-HAc buffer solution and in the presence of azomethine-H (AMH), the gold nanorod particles exhibited a strong resonance Rayleigh scattering (RRS) peak at 404 nm. In the presence of boric acid, it reacts with AMH to form AMH-boric acid (AMH-B) complexes. When the complexe as a receptor close to the gold nanorod as a donor, the resonance Rayleigh scattering energy transfer (RRS-ET) take placed that resulted in the Rayleigh scattering signal quenching. With the increase of the concentration of boric acid, the formed complexes increased, the scattering light energy of gold nanorod transfer to the complexes increased, resulting in the Rayleigh scattering intensity linearly reduced at 404 nrn. The decreased RRS intensity responds linearly to the concentration of boron over 10~750 ng . mL-1 B, with a regress equation of ΔI404 nm =3. 53c+24 and a detection of 5 ng mL-1 B. The influence of coexistence substances on the RRS-ET determination of 2. 3 X 10(-7) mol . L-1 B was considered in details. Results showed that this new RRS-ET method is of high selectivity, that is, 4 X 10(-4) mol . L-1 Mn2+, Cd2+, Zn2+, Bi+, Na+, Al3+, glucose, Hg2+, IO3-, F-, SO(2-)3, SiO3-, NO3-, CIO4-, H2O2, mannitol, glycerol, and ethylene glycol, 4X 10(-5) mol . L-1 L-tyrosine, and 2 X 10(-4) mol . L-1 L-glutamic acid do not interfere with the determination. Based on this, a new sensitive, selective, simple and rapid RRS-ET method has been developed for the determination of trace boron in six mineral water samples that contain 24. 9, 29. 3, 57. 9, 59. 0, 84. 9, and 105. 1 ng . mL-1 B, with relative standard deviation of 1. 6%~ 4. 1% and recovery of 95. 61~9. 6%.

[Fluorescence Determination of Trace Se with the Hydride-K13-Rhodamine 6G System].

Se is a necessary trace element for human and animals, but the excess intake of Se caused poison. Thus, it is very important to determination of Se in foods and water. The target of this study is development of a new, sensitive and selective hydride generation-molecular fluorescence method for the determination of Se. In 0. 36 mol . L-1 sulfuric acid, NaBH4 as reducing agent, Se (IV) is reduced to H2 Se. Usin3-g I solution as absorption liquid3, I- is reduced to I- by H2Se. When adding rhodamine 6G, Rhodamine 6G and I3- form association particles, which lead to the fluorescence intensity decreased. When Se(IV) existing, Rhodamine 6G and I3- bind less, And the remaining amount of Rhodamine 6G increase. So the fluorescence intensity is enhanced. The analytical conditions were optimized, a 0. 36 ml . L-1 H2SO4, 21. 6.g . L-1 NaBH4, 23.3 µm . L-1 rhodamine 6G, and 50 µmol . L-1 KI3 were chosen for use. When the excitation wavelength is at 480nm, the Rayleigh scattering peak does not affect the fluorescence recording, and was selected for determination of Se. Under the selected conditions, Se(IV) concentration in the 0. 02~0. 60 µg . mL-1 range and the increase value of the fluorescence intensity (ΔF) at 562 nm linear relationship. The linear regression equation is ΔF562 nm =12. 6c + 20. 9. The detecton limit was 0.01 µ.g . L-1. The influence of coexistence substances on the hydride generatin-molecular fluorescence determination of 5. 07 X10(-6) mol . L-1 Se(IV) was considered in details. Results showed that this new fluorescence method is of high selectivity, that is, 0. 5 mmol. L-1 Ba2+, Ca2+, Zn2+ and Fe3+, 0. 25 mmol . L-1 . Mg2+, 0. 05 mmol . L-1 K+, 0. 2 mmol . L-1 Al3+, 0. 025 mmol . L-1 Te(VI) do not interfere with the determination. The influence of Hg2+, CD2+ and Cu2+ that precipitate with Se(IV), can be eliminated by addition of complex reagent. This hydride generation-molecular fluorescence method has been applied to determination of trace Se in water samples,

[Resonance Rayleigh scattering determination of trace tobramycin using aptamer-modified nanogold as probe ].

Nanogold (NG) was prepared using NaBH4 reduction of HAuCl4. The NG was modified by the tobramycin-aptamer to obtain a stable Apt-NG probe for tobramycin. The three aptamers containing 15, 21 and 27 bases were examined, and results showed that the aptamer with 21 bases was best and was chosen for use. In pH 6. 8 PBS buffer solution and in the presence of NaCl, the Apt-GN probes were not aggregated. When tobramycin was added, it reacted with the Apt of Apt-NG probe to form a very stable Apt-Tbc complex and released NGs that were aggregated into big particles under the action of NaCl with three resonance Rayleigh scattering peaks at 285, 368 and 525 nm respectively. The resonance Rayleigh scattering peak increased at 368 nm due to the formation of big NG particles from the probe. The effect of pH buffer solution, its volume, and Apt-GN probe concentration on the ΔI value was considered. A 200 µL pH 6. 8 PBS buffer solution and 19. 1 nmol · L(-3) Apt-GN, giving max ΔI value, were chosen for use. Under the chosen conditions, the increased resonance Rayleigh scattering intensity ΔI368 nm was linear with Tbc concentration in the range of 1.9-58.3 ng mL(-3), with a regress equation of ΔI = 35.3c-23 and a detection limit of 0.8 ng · mL(-3) Tbc. A 10.0, 20.0 and 30.0 ng mL-3 Tbc was determined five times respectively, and the relative standard deviations were 6.8%, 5.0% and 4.4%. The influence of some foreign substances was examined on the determination of 38.9 ng · mL(-3) Tbc, within ±10% related error. Results showed that a 80 times of Zn2+, 40 times of L-glutamic acid, Cu2+, Mg2+ and Ca2+, 20 times of glucose and terramycin, 10 times of L-phenylalanine and glycin, 2 times of L-aspartic acid, and 6 times of bovine serum albumin (BSA) and human serum albumin (HSA) do not interfere with the RRS determination of Tbc. The results showed that this aptamer-nanogold RRS method is of good selectivity. Tbc in real sample was analyzed, and the analytical result was in agreement with that of reference results, with a relative standard deviation of 6.5%-7.6% and a recovery of 95.0%-107%.

[Resonance Rayleigh scattering determination of trace ozone based on the cationic surfactant association particles].

In the presence of pH 4.0 HAC-NaAC buffer solution, using H3BO3-KI (BKI) as absorption solution, O3 oxidized KI to produce I2, and it reacted with excess I- to form I3- that combined with the cationic surfactant (CS) such as cetylpyridinium chloride (CPCl), tetradecyl pyridinium bromide (TPB), cetyl trimethyl ammonium bromide (CTMAB), and tetradecyl dimethylbenzyl ammonium chloride (TDMAC) to produce stable (CS-I3)n association particles, which exhibited a strong resonance Rayleigh scattering (RRS) peak at 470 nm. Under the chosen conditions, as the concentration of O3 (C) increased, the concentration of I3- increased, and the RRS intensity at 470 nm (1470 nm) increased due to more association particles forming. The increased RRS intensity I470 nm was linear with O3 concentration. For the four CS systems, the linear range was 15-50, 50-100, 5-25 and 1-50 micromol x L(-1) O3 respectively. The regression equation is delta I = 8.81c-4.01, delta I = 5.44c-3.11, delta I = 15.39c-1.55, and delta I = 16.88c + 0.51. The detection limit is 4.9, 12, 2.85 and 0.56 micromol L(-1) O3 respectively. The influence of some foreign substances was examined on the determination of 2.5 x 10(6) mol x L(-1) O3, within +/- 10% relative error. Results showed that a 4.0 x 10(-5) mol x L(-1) Hg2+, 8.7 X 10(-5) mol x L(-1) Fe3+, 5.0 x 10(-5) mol x L(-1) Ca2+, 2.5 x 10(-5) mol L(-1) Zn2+ and Cu2+, 2.8 x 10(-6) mol x L(-1) Pb2+ and Cr3+, 4.2 x 10(-5) mol x L(-1) Mg2+, Mn2+ and Ba2+ do not interfere with the RRS determination. This showed that this RRS method is of good selectivity. The TDMAC system is most sensitive, and was chosen to detect O3 in air samples. The analytical results were in agreement with that of spectrophotometry results. Further more, laser scattering technique was utilized to examine the particle size distribution of (TDMAC-I3)n system. Results indicated that the particle size located in the range of 190-531 nm, in the absence of O3. Upon addition of O3, the excess KI reacted with O3 to produce I3-, and I3- interacted with the TDMAC to form (TDMAC-I3)n associated particles with a size range of 1,106-3,091 nm. This test identified that there are associated particles in the TDMAC system.

[DNAzyme cracking-nanogold resonance Rayleigh scattering spectral method for the determination of trace Cu2+].

In the condition of pH 7.0 HEPES buffer solution and 0.19 mol x L(-1) NaCl, the substrate strand DNA (SS) and the enzyme strand DNA (ES) hybridized into a double-stranded DNA (dsDNA) at 80 degrees C. The substrate chain of dsDNA could be cracked by Cu2+, and the released single-stranded DNA (ssDNA) were adsorbed on the nanogold(NG) surface to produce a stable NGssDNA conjugate. The unprotected NG was aggregated to form NG aggregation (NGA) that exhibited a resonance Rayleigh scattering (RRS) peak at 627 nm. When the Cu2+ was added, the NGssDNA increased, and the NGA decreased that caused the RRS intensity decreasing at 627 nm, and the solution color changed from blue to red. The decreased RS intensity deltaI was linear with the Cu2+ was added, the NGssDNA increased, and the NGA decreased that caused the RRS intensity decreasing at 627 nm, the solution color changed from blue to red. The decreased RS intensity deltaI was linear to the Cu2+ concentration in the range of 15-1 250 nmol x L(-1), with a regression equation of deltaI = 0.17c-2.3, coefficient of 0.989 5 and a detection limit of 8 nmol x L(-1) Cu2+. In addition, the influence of foreign substances on the determination of 0.75 micromol x L(-1) Cu2+ was considered. The results show that 3 micro mol x L(-1) Ca2+, Pb2+ and Hg2+, 2 micromol x L(-1) Fe2+, 1 micromol x L(-1) Sn2+, 4 micromol x L(-1) Al3+, 12 micromol x L(-1) Mn2+, 4 micromol x L(-1) Co2+ and Ni2+ did not interfered with the determination. This indicates that this method has good selectivity. This new, rapid, sensitive, selective RRS method was applied to the determination of Cu2+ in water, with satisfactory results.

[Resonance scattering detection of trace Hg2+ using aptamer modified AuSe nanoalloy].

Under the condition of sodium citrate as stabilizer, the gold-selenium (AuSe) nano-alloy was prepared by sodium borohydride reduction procedure, and was modified by single-strand aptamer to obtain an aptamer nano-alloy probe (apta-AuSe) for Hg(II). In pH 6.8 Na2HPO4-NaH2PO4 buffer solution and in the presence of NaCl of 33 mmol L(-1), the Apta-AuSe probe is not aggregation. The apta-AuSe interacts with Hg2+ to form stable double-strand T-Hg(II)-T mismatches and to release AuSe nano-alloy particles from the probe. The released AuSe nano-alloy particles (20:1) aggregated to form bigger clusters that resulted in the resonance scattering (RS) intensity (I590 nm) increasing at 590 nm. The increased intensity delta I590 nm was proportional to the Hg2+ concentration from 1.3 to 1466 nmol L(-1), with a detection limit of 0.74 nmol L(-1). The regress equation was delta I590 nm = 0.603c + 2.0. Thus, a new resonance scattering (RS) spectroscopy of apta-AuSe was applied to the analysis of trace mercury ion. This simple, rapid, selective and sensitive aptamer AuSe nano-alloy RS assay was applied to the determination of Hg2+ in wastewater, with satisfactory results.

[Resonance scattering detection of trace Hg2+ using herring sperm DNA modified nanogold].

In pH 7.0 tris-HCl buffer solutions and in the presence of 0.017 mol x L(-1) NaCl, herring sperm DNA was combined with gold nanoparticles in size of 10 nm to form stable complex, and the NaCl did not cause the aggregation of the gold nanoparticles. Upon addition of Hg2+, that reacted with DNA to form more stable complex of Hg(2+)-DNA, and the gold nanoparticles aggregated to from larger nanogold clusters that led to considerable enhancement of the resonance scattering intensity at 572 nm enhanced considerably. The effect of GN concentration, DNA concentration, NaCl concentration, incubation time, and temperature, and ultrasonic irradiation was considered respectively, the conditions of 3.87 microg x mL(-1) GN, 11.7 microg x mL(-1) DNA, pH 7.0 Tris-HCl buffer solutions, 17 mmol x L(-1) NaCl, and incubation 10 min at 37 degrees C under the ultrasonic irradiation were chosen for use. Under the conditions, the enhanced resonance scattering intensity at 572 nm was linear to the Hg2+ concentration in the range of 3.3-3 333.3 nmol x L(-1), with regress equation of delta572 nm = 0.019c+5.0, coefficient of 0.999 1, and a detection limit of 2.5 nmol x L(-1) Hg2+. Results of interference tests showed that 30 micromol x L(-1) Mn2+, 33 micromol x L(-1) Mg2+ and Zn2+, 100 micromol x L(-1) Cd2+, 200 micromol x L(-1) Fe3+, and 420 micromol x L(-1) Mo6+, Pb2+ and Cu2+ did not interfered with the determination of 0.33 micromol x L(-1) Hg2+. That is, this resonance scattering spectral assay is of good selectivity. This assay was applied to the detection of Hg(II) in water sample, with a relative standard deviation of 5.1%, and the results were in agreement with that of the cool vapor atomic absorption spectrophotometry.

[Resonance scattering spectral detection of trace K+ by aptamer-modified nanogold probe].

In pH 7.0 Na2HPO4-NaH2PO4 buffer solution, nanogold particles interacted with the aptamer to form a stable aptamer-nanogold complex that was not aggregation by NaCl. At 80 degrees C, K+ and aptamer folded to form a stable G-quadruplex that released nanogold particles, the uncombined nanogold particles aggregated to large nanogold clusters that caused the increase in resonance scattering (RS) intensity at 563 nm in high concentration of NaCl, and the laser scattering showed that the average diameter was 120 nm. In the present paper, the resonance scattering spectral characteristics of K+ -ssDNA1-Au, K+ -ssDNA2-Au and K+ -aptamer-Au systems were investigated, and the structural changes of aptamer were studied by circular dichroism spectral technology. Effects of pH value, NaCl concentration, nanogold concentration, aptamer concentration, and the reactation temperature and time on the resonance scattering intensity were considered in detail. The influence of coexistent substances on the determination of K+ was investigated, result showed that the common heavy metal ions such as Cu2+, Mg2+, Pb2+, Ca2+, Al3+, Zn2+ and Fe3+ do not interfere with the determination, and the method has good selectivity. Under the conditions selected, a 0. 67-3 350 micromol x L(-1) K+ can be detected by the aptamer-nanogold RS assay, with a detection limit of 0.3 micromol x L(-1) K+, regression equation deltaI = 0.167c-0.7, and a coefficient of 0.9932. The method was used for analysis of K+ in serum sample with the results consistent with the ion-selective electrode method.

[Fluorescence analysis of trace glucose using glucose oxidase and horseradish peroxidase].

In acetate buffer solution and in the presence of glucose oxidase (GOD), glucose reduced the dissolved oxygen to form H2O2 that oxidized catalytically the excess KI to from I3- by horseradish peroxidase (HRP). The I3- combines respectively with rhodamine S (RhS), rhodamine 6G(Rh6G), butyl-rhodamine B(b-RhB) and rhodamine B(RhB) to form RhS-I3, Rh6G-I3, b-RhB-I3 and RhB-I3 associated particles that result in fluorescence quenching at 556, 556, 584 and 584 nm, respectively. Under the optimal conditions, the concentration of glucose in the range of 0.083-9.99, 0.17-8.33, 0.33-8.33 and 0.33-9.99 micromol x L(-1) is linear with their fluorescence quenching at 556, 556, 584 and 584 nm, with detection limits of 0.059, 0.17, 0.21 and 0.16 micromol x L(-1) glucose. And the regression equation was deltaF = 40.0c + 3.0, deltaF = 23.9c + 8.1, deltaF = 25.6c + 4.2, and deltaAF = 18.4c + 0.8, respectively. The RhS system was the most sensitive and stable, and was chosen for use. Influence of some foreign substances on the RhS fluorescence quenching determination of 6.67 micromol x L(-1) glucose was examined, with a relative error of +/- 10%. Results showed that 1000-fold Mg2+ and Cu2+, 300-fold Mn2+, 100-fold Zn2+, Al3+ and Co2+, 60-fold L-tyrosine, urea and nicotinic acid, 50-fold Fe3+, HSA and BSA, 10-fold sucrose, vitamin B2, L-lysine, L-glutamic acid and L-cystine did not interfere with the determination. This RhS fluorescence quenching assay was applied to the determination of glucose in the serum samples with satisfactory results.

[Flame atomic absorption spectrometric determination of H2O2 using (Au) core (Ag) shell nanoparticles].

The 10 nm gold nanoparticles were prepared by Frens procedure. Using tri-sodium citrate as reducer of AgNO3, and 10 nm gold nanoparticles as seed, the (Au)core(Ag)shell nanoparticles the size of about 30 nm were prepared at 90 degrees C for 10 min. Then it was separated by centrifuge at 10000 r x min(-1) for 15 min to obtain pure (Au)core(Ag)shell nanoparticles. In pH 3.8 sodium acetate-acetic acid buffer solution, hydroxyl free radical from Fenton reaction between Fe(II)-H2O2 oxidized (Au)core(Ag)shell nanoparticles to form silver ions. The silver ions in the centrifugal solutions can be measured by flame atomic absorption spectrometry at 328.1 nm. The silver ions in the centrifugal solutions increased with the H2O2 concentration increasing, and the absorption value at 328. 1 nm was enhanced linearly. The influence factors such as pH value, buffer solution volume, concentration of (Au)core(Ag)shell and Fe(II), reaction temperature and time, and centrifuging velocity and time were considered, respectively. Under the conditions of 0.20 mL pH 3.8 sodium acetate-acetic acid buffer solution, 50 microL of 2.0 mmol x L(-1) FeSO4, 60 microL of 2.94 x 10(-4) mol x L(-1) (Au)core(Ag)shell nanoparticle solution, reaction time of 20 min at 60 degrees C, and centrifugalization at 14 000 rpm for 10 min, the increased value deltaA is proportional to the H2O2 concentration (c) from 2. 64 to 42.24 micromol x L(-1), with a detection limit of 0.81 micromol x L(-1). The regress equation was deltaA = 0.014c-0.013 1, with a coefficient of 0.998 4. The effect of foreign substances such as 100-times glucose, Cu2+, Mg2+, Ca2+, 50-times urea, bovine serum albumin, Mn2+, Pb2+, and 30-times Cr3+ on the determination of 13.2 micromol x L(-1) H2O2 was examined respectively, with a relative error of +/- 10%. Results showed that there was no interference. This assay showed high sensitivity and good selectivity for quantitative determination of H2O2 in waste water samples, with satisfactory results. The analytical results were in agreement with that of the reference results.

[A new immuno-nanosliver resonance scattering spectral probe for assay of IgG].

Using tri-sodium citrate as reducer, stable silver nanoparticles the size of about 20 nm were prepared by the microwave high pressure procedure with simplicity and rapidity. At pH 9.0, sliver nanoparticle was used to label goat anti-human IgG (GIgG) to obtain an immuno-nanosilver resonance scattering spectral probe (AgGIgG) for IgG. In pH 6.0 buffer solution and in the presence of polythylene glycol (PEG) and KCl, the immune reaction of IgG with AgGIgG took place, the silver nanoparticles released from AgGIgG produced aggregations, and the resonance scattering intensity at 485 nm (I(485 nm)) was enhanced greatly. The influence factors such as pH value, buffer solution volume, concentration of AgGIgG, KCl, PEG-4000, PEG-6000, PEG-10000 and PEG-20000, incubation temperature and time were considered, respectively. Under the conditions of 0.40 mL of pH 6.0 phosphate buffer solution, 1.20 mL of 9.8 microg x mL(-1) AgGIgG, 0.20 mL of 20% PEG-6000, 0.50 mL of 10% KCl, and ultrasonic irradiation for 25 min at room temperature, the increased intensity deltaI(485 nm), was proportional to the IgG concentration (c(IgG)) from 0.004 to 0.48 microg x mL(-1), with a detection limit of 2.4 ng x mL(-1). The regress equation was deltaI485 nm = 76.8c(IgG) + 4.7. The effect of foreign substances such as 20 microg x mL(-1) Ni2+, Fe2+, Pb2+ and BSA,60 microg x mL(-1) Cu2+, Ca2+ and HSA,60 microg x mL(-1) Mg2+ and Mn2+, 320 microg x mL(-1) Zn2+, glucose and urea on the deltaI(485 nm) was examined, respectively. Results showed that there was no interference. This assay showed high sensitivity and good selectivity for quantitative determination of IgG in human serum with satisfactory results. The analytical results were in agreement with that of the reference results.

[Fluorescence quenching assay of ultratrace horseradish peroxidase using rhodamine dye].

In acetate buffer solution, the reaction of H2O2 with KI was catalyzed by horseradish peroxidase (HRP) to form I3-. The I3- combined respectively with rhodamine S(RhS), rhodamine 6G(Rh6G), rhodamine B(RhB) and butyl-rhodamine B(b-RhB) to form RhS-I3, Rh6G-I3, RhB-I3 and b-RhB-I3 association particles, resulting in the fluorescence quenching at 580, 580, 554 and 554 nm, respectively. The effect of pH value, rhodamine dye concentration, KI concentration, H2O2 concentration, reaction temperature and time on the fluorescence quenching intensity (deltaF) of the four catalytic systems was considered respectively. For the RhS, Rh6G, RhB and b-RhB catalytic systems, pH 4.6-3.2 x 10(-5) mol x L(-1) RhS-4 x 10(-3) mol x L(-1) KI-1.30 x 10(-5) mol x L(-1) H2O2-25 degrees C-20 min, 4.8-2.4 x 10(-5) mol x L(-1) Rh6G-4 x 10(-3) mol x L(-1) KI-2.59 x 10(-5) mol x L(-1) H2O2-25 degrees C-20 min, 4.6-1.6 x 10(-5) mol x L(-1) RhB-4 x 10(-3) mol x L(-1) KI-2.16 x 10(-5) mol x L(-1) H2O2-25 degrees C-20 min, and 4.6-1.6 x 10(-5) mol x L(-1) b-RhB-4 X 10(-3) mol x L(-1) KI-3.02 x 10(-5) mol x L(-1) H2O2-25 degrees C-20 min were chosen for use respectively. Under the optimal conditions, the HRP linear range was 8-6 400 pg x mL(-1) for the RhS catalytic system, 40-4 000 pg x mL(-1) for the Rh6G catalytic system, 32-3 200 pg x mL(-1) for the RhB catalytic system and 40-6 400 pg x mL(-1) for the b-RhB catalytic system, with a detection limit of 3.2, 3.0, 2.4 and 3.7 pg x mL(-1) HRP, respectively. The regress equation of the four catalytic systems was deltaF = 0.061 1c+39.6, deltaF = 0.047 2c+50.4, deltaF = 0.138 6c+34.2 and deltaF = 0.026 25c+36.72, with a correlation coefficient of 0.997 9, 0.999 0, 0.997 3 and 0.996 9, respectively. The RhS catalytic system was most sensitive, and was chosen for the determination of HRP. The influence of foreign substance on the RhS assay of 3.5 ng x mL(-1) HRP was examined, with a relative error of +/- 10%. A 3000-times L-glutamic acid, L-lysine, Ca2+, Mg2+, Cu2+, Fe3+, Zn2+ and vitamin B6, 1000-times HAS etc did not interfere with the assay. This showed that the assay has good selectivity. The RhS fluorescence quenching assay was applied to the determination of HRP in the solution of hepatitis B surface antibody labeling HRP, with satisfactory results.

[Study on the energy transfer fluorescence quenching reaction of acridine orange-4-(2-pyridylazo) resorcinol-V(V) system and analytical application].

An energy transfer technique for 4-(2-pyridylazo) resorcinol (PAR)-vanadium(V) and acridine orange (AO) was studied, and the optimum conditions of energy transfer system were also experimented. It was found that in citrate-Na2 HPO4 buffer solution at pH = 5.5, energy transfers from AO to vanadium(V)-PAR complexes. A new method based on energy transfer fluorescence quenching for the determination of trace vanadium(V) with AO-PAR-V(V) was established. The equation of linear regression is deltaF = 165.4c+2.5, and the determination range of vanadium is 0.012-0.5 microg x mL(-1), with detection limit of 0.004 5 microg x mL(-1). The correlation coefficient is R = 0.998 5, and relative standard deviation is 0.6%. The fluorescence reaction is completed within 15 minutes, and relative fluorescence intensity remains unchanged for 2.5 hours. The influence of foreign ions on the determination of V (0.5 microg x mL(-1)) was examined, with a related error of 5%. The method has been used in the determination of trace vanadium in biological samples with the relative error of 6.98%, which meets the requirements of trace analysis.

[Immune resonance scattering spectral analysis of fenvalerate].

In the pH 7.2 Na2HPO4-NaH2PO4 buffer solutions and in the presence of PEG-6000, fenvalerate (Fen) antisera was combined with Fen specifically, and aggregated to form immune complex particles that exhibited five resonance scattering peaks at 350, 390, 420, 440 and 480 nm respectively. The peak at 390 nm was the strongest and was chosen for use. Fen concentration (c) in the range of 0.20 to 6.40 microg x mL(-1) was proportional to the resonance scattering intensity at 390 nm. Its regression equation was DeltaIRS 23.05c-1.39, the correlation coefficient was 0.9978, and the detection limit was 0.07 microg x mL(-1). Effects of buffer solution type, pH value, buffer solution volume, fenvalerate antisera concentration, PEG-6000 concentration, incubation temperature and time on the resonance scattering intensity were considered in detail. With pH (5.8-8.0) increasing, the IRS and Ib all decreased. When the pH value was at 7.2, the DeltaIRS was bigger. Three buffer solutions of pH 7.2, including Na2HPO4-citric acid, Na2HPO4-KH2PO4 and Na2HPO4-NaH2PO4, were examined. The pH 7.2 Na2HPO4-NaH2PO4 buffer solution gives the biggest DeltaIRS value. PEG-6000 could enhance the DeltaIRS value. When the concentration of PEG-6000 was 50.0 mg x mL(-1), the DeltaIRS was achieved at max. Fen was a stable chemical. The IRS increased within 20 min,while the DeltaIRS remained constant when incubation time was in the range of 20-40 min. The condition of a pH 7.2 Na2HPO4-NaH2PO4 buffer solution-50.0 mg x mL(-1) PEG-6000-6.67 microg x mL(-1) Fen antisera-30 degrees C-incubation time 20 min was chosen. According to the procedure, the influence of foreign substances on the determination of 1.60 microg x mL(-1) Fen was examined, within a relative error of +/- 5%. Results showed that the following coexistent substances had no impact on the RS assay: 96 microg x mL(-1) ametryne, 96 microg x mL(-1) m-aminotoluene, 48 microg x mL(-1) simetryne, 48 microg x mL(-1) p-aminotoluene,80 microg x mL(-1) BSA, 80 microg x mL(-1) HSA, 80 microg x mL(-1) Fe3+, 80 microg x mL(-1) Mg2+, 160 microg x mL(-1) Ca2+, and 160 microg x mL(-1) glucose. The results indicated that this RSS assay has good selectivity. This immune resonance scattering spectral assay was applied to the determination of Fen in waste water samples with satisfactory results. The recovery was in the range of 92.91%-101.25%, and the relative standard deviation was in the range of 1.71%-4.80%.