An Innovative Metal Ions Sensitive “Test Paper” Based on Virgin Nanoporous Silicon Wafer: Highly Selective to Copper(II)

Abstract

Developing an innovative “Test Paper” based on virgin nanoporous silicon (NPSi) which shows intense visible emission and excellent fluorescence stability. The visual fluorescence quenching “Test Paper” was highly selective and sensitive recognizing Cu2+ at μmol/L level. Within the concentration range of 5 × 10−7 ~50 × 10−7mol/L, the linear regression equation of IPL = 1226.3-13.6[CCu2+] (R = 0.99) was established for Cu2+ quantitative detection. And finally, Cu2+ fluorescence quenching mechanism of NPSi prober was proposed by studying the surface chemistry change of NPSi and metal ions immersed-NPSi using XPS characterization. The results indicate that SiHx species obviously contribute to the PL emission of NPSi, and the introduce of oxidization state and the nonradiative recombination center are responsible for the PL quenching. These results demonstrate how virgin NPSi wafer can serve as Cu2+ sensor. This work is of great significant to promote the development of simple instruments that could realize rapid, visible and real-time detection of various toxic metal ions.

Two-Dimensional Fluorescent Strategy Based on Porous Silicon Quantum Dots for Metal-Ion Detection and Recognition

“…We also chose similar ions that can effectively quench the PL of LuPSiNPs. As shown in Figures S7 and S8, both Ag + and Cu 2+ display high quenching coefficients ( K sv ), which was similar to the reported results, , but Ag + led to a red shift of PL, while Cu 2+ obviously induced a blue shift. This result could be explained by their different quenching mechanisms.…”

Implementing a Single Gate Heterostructure Tunnel FET as a Low-Power Photosensor with Improved Sensitivity

“…These energy transfer mechanisms have led to the optical production of charge carriers over the photosensitive region. 5,6 When light strikes the device's sensitive area, photons are absorbed, forming optical charge carriers in the illumination region. 7,8 The use of field-effect transistors (FETs) as a photosensor is one of the most appealing options due to its compatibility with complementary metal-oxide semiconductor (CMOS) technology.…”

Performance investigation of a charge plasma tunnel FET with SiGe source pocket as a photosensor

“…As a result, light-absorbing particles are in charge of producing transient excited states, which have entirely different chemical and physical properties. The optical generation of charge carriers over the photosensitive region has been caused by these energy transformation phenomena [33,34].…”