CONTENTSshould be inexpensive disposable chips or cartridges that include microfluidic features to provide or control sample preparation, flow rate, mixing with reagents, reaction time associated with binding events, filtration of nonanalytical components of the sample, separation of interfering agents and of multiple analytes, and an effective measurement capability. 4 POC diagnostics have been extensively reviewed in recent years, from the points of view of both use 5 and development. 6 The reviews have included coverage of micrototal analysis systems (μTAS), 7 miniaturized isothermal nucleic acid amplification 8 and molecular biological techniques for gene assay, 9 current and anticipated technology for POC infection diagnosis, 10 and microfluidic-based systems leading toward point-of-care detection of nucleic acids and proteins, 11 including multiplexing and labelfree methods. 12 Developments in this area include not only technology but also reliable measurement targets, which in some important areas remain elusive: progress toward viable point-ofcare protein biomarker measurements for cancer detection and diagnostics has been reviewed. 13 We review here the present status of POC diagnostics, emphasizing in particular the past 4 years, then extrapolate their progress into the future. Included are IVD tests for biochemical targets of all sorts relevant to human health, diagnosis, and therapy, as enumerated above. We begin with an overview of the different classes of bioanalytical targets. Then, after setting the context using the well-established glucose and pregnancy POC tests, recent progress in key enabling technologies is reviewed, including traditional and advanced lateral flow approaches, printing and laminating technologies, a range of microfluidic advances, progress in surface chemistry and the control of nonspecificbinding, and developments in labeled and label-free detection approaches. A number of specific innovative examples, in both commercial products and academic POC research, are presented, including assays based on binding to proteins, nucleic acids, and aptamers, with separate sections devoted to blood chemistry, coagulation, and whole cells. We close with trends and future perspectives.Why POC Diagnostics? Time POC measurements provide results rapidly, where needed, and often with major time savings: samples do not travel to a laboratory to await the attention of a skilled technician; results do not wait to be transmitted and collected. Rather, the doctor, nurse, care-giver, patient, or consumer initiates the test and receives the results on the spot. Inevitably this saves time, but speed must not be traded for accuracy or reliability. Figure 1. Idealized POC device. Adapted with permission from ref 6a.

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Several remote observations have indicated that water ice may be presented in permanently shadowed craters of the Moon. The Lunar Crater Observation and Sensing Satellite (LCROSS) mission was designed to provide direct evidence. On 9 October 2009, a spent Centaur rocket struck the persistently shadowed region within the lunar south pole crater Cabeus, ejecting debris, dust, and vapor. This material was observed by a second "shepherding" spacecraft, which carried nine instruments, including cameras, spectrometers, and a radiometer. Near-infrared absorbance attributed to water vapor and ice and ultraviolet emissions attributable to hydroxyl radicals support the presence of water in the debris. The maximum total water vapor and water ice within the instrument field of view was 155 ± 12 kilograms. Given the estimated total excavated mass of regolith that reached sunlight, and hence was observable, the concentration of water ice in the regolith at the LCROSS impact site is estimated to be 5.6 ± 2.9% by mass. In addition to water, spectral bands of a number of other volatile compounds were observed, including light hydrocarbons, sulfur-bearing species, and carbon dioxide.

We present a self-powered integrated microfluidic blood analysis system (SIMBAS) that does not require any external connections, tethers, or tubing to deliver and analyze a raw whole-blood sample. SIMBAS only requires the user to place a 5 μL droplet of whole-blood at the inlet port of the device, whereupon the stand-alone SIMBAS performs on-chip removal of red and white cells, without external valving or pumping mechanisms, followed by analyte detection in platelet-containing plasma. Five complete biotin-streptavidin sample-to-answer assays are performed in 10 min; the limit of detection is 1.5 pM. Red and white blood cells are removed by trapping them in an integral trench structure. Simulations and experimental data show 99.9% to 100% blood cell retention in the passive structure. Powered by pre-evacuation of its PDMS substrate, SIMBAS' guiding design principle is the integration of the minimal number of components without sacrificing effectiveness in performing rapid complete bioassays, a critical step towards point-of-care molecular diagnostics.

We report an atomic force microscopy (AFM) investigation of generation 4 and 8 (G4, G8) polyamidoamine (PAMAM) starburst dendrimers adsorbed on Au (111) surfaces. Heights measured for isolated, adsorbed dendrimers indicate they are substantially more oblate than expected from their spherical shapes in solution. By controlling dendrimer concentration and exposure time during adsorption, modified surfaces ranging from isolated molecules to near-monolayer coverages were obtained. Exposure of surfaces bearing adsorbed isolated dendrimers to hexadecanethiol solutions changed their conformation from oblate to prolate as more stable thiol-Au bonds replaced some of the amine-Au bonds. For surfaces of near-monolayer coverage, exposure to hexadecanethiol caused the dendrimers to gradually agglomerate, forming dendrimer "pillars" up to 30-nm high.There is a vast literature pertaining to dendrimers, 1 but only a few reports of individual dendrimer visualization using TEM, 2 STM, 3 and AFM, 4,5 or showing the grainy structure of a dendrimer monolayer using AFM. 6 For our study, dendrimers 7 were adsorbed onto atomically flat Au (111) facets by dipping the substrate 8 into either a 10 -7 M ethanolic solution (for monolayers) or a 10 -9 M solution (for isolated molecules) for 45 s. Au substrates were then alternately rinsed with ethanol and water. To alter the shape of isolated dendrimers, samples were soaked for 4 h in a 1 mM ethanolic solution of hexadecanethiol and then rinsed as described above. To induce agglomeration, dendrimer monolayers were soaked in hexadecanethiol solution for 24-110 h. Measurements made in a minimum of three different areas within each of five well-separated 10 × 10 µm sites on each of two identically prepared Au substrates (30 areas altogether) yielded consistent results. Tapping-mode AFM measurements (topographical data only) in air were performed using a Nanoscope III STM with an E-type scanner. 9 We investigated two different sizes of dendrimers: the soft and deformable G4 (ideal sphere diameter, 4.5 nm) and the larger G8 having a harder exterior (ideal sphere diameter, 9.7 nm). 7 The results for G8 are displayed in parts a-c of Figure 1. Figure 1a shows the topography of the Au surface covered with isolated G8 dendrimers. In the upper right corner, an Au step edge is visible, its height (0.24 nm) providing a vertical reference scale. The measured diameter of the adsorbed G8 dendrimer is approximately 20 nm, but as discussed below, the lateral dimensions are convoluted with the AFM tip shape. Nevertheless, the height data in Figure 1b are reliable. Within experimental error (0.1-0.2 nm) and on the basis of data from more than 100 single dendrimers, the height of the G8 dendrimers on a naked Au surface ranges from 3.5 to 4.0 nm, or about 60% less than the ideal-sphere diameter of 9.7 nm. The variation in height and lateral size of the surface-confined dendrimers may arise from a distribution of molecular sizes resulting from the synthesis, 2b tipinduced deformation of the dendrimers, 6,10-12 ...

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