Harnessing virus flexibility to selectively capture and profile rare circulating target cells for precise cancer subtyping.

The effective isolation of rare target cells, such as circulating tumor cells, from whole blood is still challenging due to the lack of a capturing surface with strong target-binding affinity and non-target-cell resistance. Here we present a solution leveraging the flexibility of bacterial virus (phage) nanofibers with their sidewalls displaying target circulating tumor cell-specific aptamers and their ends tethered to magnetic beads. Such flexible phages, with low stiffness and Young's modulus, can twist and adapt to recognize the cell receptors, energetically enhancing target cell capturing and entropically discouraging non-target cells (white blood cells) adsorption. The magnetic beads with flexible phages can isolate and count target cells with significant increase in cell affinity and reduction in non-target cell absorption compared to magnetic beads having rigid phages. This differentiates breast cancer patients and healthy donors, with impressive area under the curve (0.991) at the optimal detection threshold (>4 target cells mL-1). Immunostaining of captured circulating tumor cells precisely determines breast cancer subtypes with a diagnostic accuracy of 91.07%. Our study reveals the power of viral mechanical attributes in designing surfaces with superior target binding and non-target anti-fouling.

Spectral Engineering of InSe Nanobelts for Full-Color Imaging by Tailoring the Thickness.

In this work, we report on the synthesis of InSe nanobelts through a catalyst-free chemical vapor deposition (CVD) growth approach. A remarkable blue shift of the peak photoresponse was observed when the thickness of the InSe nanobelt decreases from 562 to 165 nm. Silvaco Technology Computer Aided Design (TCAD) simulation reveals that such a shift in spectral response should be ascribed to the wavelength-dependent absorption coefficient of InSe, for which incident light with shorter wavelengths will be absorbed near the surface, while light with longer wavelengths will have a greater penetration depth, leading to a red shift of the absorption edge for thicker nanobelt devices. Considering the above theory, three kinds of photodetectors sensitive to blue (450 nm), green (530 nm), and red (660 nm) incident light were achieved by tailoring the thickness of the nanobelts, which can enable the spectral reconstruction of a purple "H" pattern, suggesting the potential application of 2D layered semiconductors in full-color imaging.

Highly Sensitive Ultraviolet and Visible Wavelength Sensor Composed of Two Identical Perovskite Nanofilm Photodetectors.

This work reports the design of a wavelength sensor composed of two identical perovskite (FA0.85 Cs0.15 PbI3 ) photodetectors (PDs) that are capable of discriminating incident wavelength in a quantitative way. Due to strong wavelength-dependent absorption coefficient, the penetration depth of the photons in the FA0.85 Cs0.15 PbI3 nanofilms increases with the increasing wavelength, leading to a gradual decrease of photo-generated current for PD1, but an increase of photocurrent in PD2, according to the theoretical simulation of Technology Computer Aided Design. This special evolution of photo-generated current as a function of wavelength facilitates the quantitative determination of the wavelength since the current ratio of both PDs monotonously decreases with the increase of wavelength from 265 to 810 nm. The average absolute error and the average relative error are estimated to be 7.6 nm and 1.68%, respectively, which are much better than other semiconductors materials-based wavelength sensors previously reported. It is believed that the present perovskite film-based wavelength sensor will have potential application in the future color/spectrum optoelectronic devices.