Metal imaging on surface of micro- and nanoelectronic devices by laser ablation inductively coupled plasma mass spectrometry and possibility to measure at nanometer range

Abstract

An analytical mass spectrometric method for the elemental analysis of nano-bioelectronic devices involved in bioengineering research was developed and applied for measurements of selected metals (Au, Ti, Pt, Cr, etc.) on interdigitated electrode array chips (IDA-chip). An imaging laser ablation inductively coupled plasma mass spectrometric (LA-ICP-MS) procedure was used to map the elements of interest on the surface of the analyzed sample. The obtained images of metals were in a good agreement and corresponded to the micro-and nanofabricated metal electrode pattern. For the analysis at nanometer resolution scale a NF-LA-ICP-MS (NF-near-field) procedure was applied, which utilize thin Ag needle to enhance laser beam energy and improve spatial resolution of the method. The results show a ϳ100ϫ enhancement of analyte signal, when the needle was positioned in the "near-field region" to the sample surface and the laser shot was performed. In addition, mass spectrometric studies of reproducibly for five separated NF-LA shots in different places of analyzed sample yielded an RSD of the measurement of 16%. io engineering (or biological engineering), including biomedical engineering and nanobiotechnology, is a new, challenging, and rapidly growing high-tech research field [1,2]. The use of biomolecules as the building blocks of higher-level functional devices will lead to applications that range from the integration of biomaterials with electronics in recognition or sensing devices [3]. Bioelectronics research also exploits to use biomolecules to perform the electronic functions that semiconductor devices currently perform, thereby offering the potential to increase integration in combination with additional functionality at the nanometer level. However, the integration of biomolecules or even whole cells with inorganic devices brings several challenges about as there are, for instance, operation of the electronic components under physiological conditions, electrically, biochemically as well as size-adapted bioinorganic interfaces, and biocompatibility of the electronic devices. The implementation of these challenges and the realization of functional bioelectronic junctions require interdisciplinary research, including microengineering, biotechnology, surface chemistry, and analytical research.The fabrication of bioelectronic component on the basis of silicon microtechnology facilitates high integration densities, high spatial resolution, combining signal recording and transducing in one device at relatively low production costs. To build and assemble bioinorganic electronic components with well defined and optimized features, it usually requires control over impurities of trace levels contaminations, which can influence the physical, electrical, magnetic, and chemical properties of thin layered systems. In particular, the biocompatibility of device can be strongly affected by organic and inorganic impurities introduced during the fabrication processes. Therefore, powerful and sensitive trace analytical techniques are ne...

Bioimaging of Metals and Proteomic Studies of Clinical Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA‐ICP‐MS)

“…Using a large laser ablation chamber, commercially available from CETAC Technologies, the Cu and Zn distribution in a 20-mm tissue section of human brain hemisphere (110 mm  65 mm) was analyzed. In contrast, small laser ablation cells for development of Nano-LA-ICP-MS using near field effect at the nm spatial resolution were devised for future application in clinical studies on single cells by Becker and coworkers [61,63,64].…”

“…The spot size of the laser beams varied between 50 and 200 mm, and the laser power density from 1 to 3 Â 10 9 W cm À2 . Ion intensities of the analytes, for example, of 64 Zn þ , were measured by LA-ICP-MS within the area of interest in different regions of the human brain tissue (e.g., human hippocampus) [38].…”

“…The measurement time for the tissue section depends on experimental parameters selected (from 1 to 8 h). In order to validate the ion images, at least two isotopes were analyzed, if available (e.g., 64 Zn þ and 66 Zn þ ). In this connection, it is proposed that the elemental distribution in nearby tissue slices should be performed under the same experimental parameters.…”

“…The 2D BN-PAGE in the pI range of 4 to 7 after colloidal Coomassie Brilliant Blue staining is illustrated on the right-hand side of Figure 17.9. The wide band in the middle of the gel was identified as bovine serum albumin by MALDI-TOF-MS. 34 S þ , 63 Cu þ , and 64 Zn þ bonded to the protein was detected by LA-ICP-MS of bovine serum albumin in five line scans of 2D BN gel, as illustrated on the left-hand side of Figure 17.10. A correlation of the maximum intensity of S from protein with the maximum intensity of 63 Cu þ and 64 Zn þ was observed.…”

Mass spectrometric imaging of elements in biological tissues by new BrainMet technique—laser microdissection inductively coupled plasma mass spectrometry (LMD-ICP-MS)

“…8,9 In singleshot measurements by NF-LA-ICP-MS, it is demonstrated that significantly enhanced ion intensity of the laser-ablated materials was monitored by double focusing sector field ICP-MS when the thin Ag needle tip was close to the sample surface due to the nearfield enhancement. [9][10][11][12] Recently, a three-dimensional movement piezo has been introduced under the sample holder to permit imaging of samples by the novel NF-LA-ICP-MS. In addition, the system for controlling the 'tip-to-sample' distance has been adapted with a dynamic non-contact feedback mode, which makes it possible to analyze biological samples.…”