Highly sensitive and a multiplex assay of viruses and viral DNAs in complex biological samples is extremely important for clinical diagnosis and prognosis of pathogenic diseases as well as virology studies. We present an effective ICP-MS-based multiplex and ultrasensitive assay of viral DNAs with lanthanide-coded oligonucleotide hybridization and rolling circle amplification (RCA) strategies on biofunctional magnetic nanoparticles (MNPs), in which single-stranded capture DNA (ss-Cap-DNA)-functionalized MNPs (up to 1.65 × 10(4) ss-Cap-DNA per MNP) were used to recognize and enrich target DNAs, and single-stranded report DNA (ss-Rep-DNA-DOTA-Ln) coded by the lanthanide-DOTA complex hybridized with the targeted DNA for highly sensitive readout of HIV (28 amol), HAV (48 amol), and HBV (19 amol). When utilizing the RCA technique in association with the design and synthesis of a "bridge" DNA and a corresponding ss-Rep-DNA-DOTA-Ho, as low as 90 zmol HBV could be detected. Preliminary applications to the determination of the viral DNAs in 4T1 cell lysates and in serum confirmed the feasibility of this ICP-MS-based multiplex DNA assay for clinical use. One can expect that this element-coded ICP-MS-based multiplex and ultrasensitive DNA assay will play an ever more important role in the fields of bioanalysis and virology and in medical studies after further sophisticated modifications.

We reported novel Ag-TiO(2)- and ZrO(2)-based photocatalytic vapor generation (PCVG) systems as effective sample introduction techniques for further improving the sensitivity of the atomic spectrometric determination of selenium for the first time, in which the conduction band electron served as a "reductant" to reduce selenium species including Se(VI) and convert them directly into volatile H(2)Se, which was easily separated from the sample matrix and underwent more effectively subsequent atomization and/or ionization. These two PCVG systems helped us to overcome the problem encountered in the most conventional KBH(4)/OH(-)-H(+) system, in that Se(VI) was hardly converted into volatile selenium species without the aid of prereduction procedures. The limits of detection (LODs) (3σ) of the four most typical Se(IV), Se(VI), selenocystine ((SeCys)(2)), and selenomethionine (SeMet) species were, respectively, down to 1.2, 1.8, 7.4, and 0.9 ng mL(-1) in UV/Ag-TiO(2)-HCOOH, and 0.7, 1.0, 4.2, and 0.5 ng mL(-1) in UV/ZrO(2)-HCOOH with the relative standard deviations (RSDs) lower than 5.1% (n = 9 at 1 μg mL(-1)) when using atomic fluorescence spectrometry (AFS) under flow injection mode. They reached 10, 14, 18, and 8 pg mL(-1) in UV/Ag-TiO(2)-HCOOH, and 6, 7, 10, and 5 pg mL(-1) in UV/ZrO(2)-HCOOH with the RSDs lower than 4.4% (n = 9 at 10 ng mL(-1)) when using inductively coupled plasma mass spectrometry (ICPMS). After the two PCVG systems were validated using certified reference materials GBW(E)080395 and SELM-1, they were applied to determine the total Se in the selenium-enriched yeast sample and used as interfaces between high-performance liquid chromatography (HPLC) and AFS or ICPMS for selenium speciation in the water- and/or enzyme-extractable fractions of the selenium-enriched yeast.

Click and analyze: the titled probe was synthesized by conjugating a sulfonyl fluoride and azido unit using click chemistry to give SF-Eu, which can react specifically with serine (Ser) in the active site of serine protease (SP). Combination of the method with (153)Eu-isotope dilution ICP/MS enables absolute protein quantification of active SPs in biological samples using only one (153)Eu(NO(3))(3) isotopic standard.

We report the design and synthesis of a trifunctional probe for seeing and counting cancer cells using both fluorescence imaging (FI) and inductively coupled plasma mass spectrometry (ICPMS) for the first time. It consisted of a guiding cyclic RGD peptide unit to catch cancer cells via targeting the α(v)β(3) integrin overexpressed on their surface, a 5-amino-fluorescein moiety for FI using confocal laser scanning microscopy (CLSM) as well as a 2-aminoethyl-monoamide-DOTA group for loading stable europium ion and subsequent ICPMS quantification of the cancer cells without the use of radioactive isotopes. In addition to FI, the LOD (3σ) of the α(v)β(3) integrin was down to 69.2-309.4 amol per cell depending on the type of the α(v)β(3)-positive cancer cells when using ICPMS and those of the cancer cell number reached 17-75. This probe developed enables us not only to see but also to count the α(v)β(3)-positive cancer cells ultrasensitively, paving a new way for early diagnosis of cancer.

Klicken und analysieren: Die im Titel genannte Sonde (SF‐Eu), die durch Klickreaktion eines Sulfonylfluorids mit einer Azido‐Einheit synthetisiert wurde, reagiert spezifisch mit Serin im aktiven Zentrum von Serinproteasen (SPs). Die Kombination der Methode mit 153Eu‐Isotopenverdünnungs‐ICP/MS ermöglicht die absolute Proteinquantifizierung aktiver SPs in biologischen Proben mit nur einem einzigen 153Eu(NO3)3‐Isotopenstandard.