ISO TS 21412:2020 download free.Nanotechnologies — Nano-objectassembled layers for electrochemical bio-sensing applications — Specification of characteristics and measurement methods.
Electrochemical electrodes can exhibit nano-enhanced performance after the deposition of nanoobjects on the electrode surface. The increased surface area, orientation, the assembled density and ability to control the bio-receptor of the nano-object layer improves the performance of nanoblosensors. Nano-bioserisor sensitivity, selectivity and reliability can be enhanced with specific nanoobjects, e.g. gold nanoparticIeslZ2ULil25l, carbon nanotubesiZil, CuS2 nanorodsl2i and silverI11I or palladium nanopbteslLfl.
Currently, most of the nano-erihanced electrochemical electrodes are fabricated by researchers in order to achieve predictable performance in their own programs without mass-production. However, the technology is maturing into a commercIal phase. Fabrtcators are offering nano-enhanced electrodes to instrument manufacturers as a platform to add additional coatings for specific sensing applications. ISO TS 21412 supports the development of material specifications for the transaction between electrode fabrications and instrument manufacturers to allow the purchase olelectrodes with predictable performance.
ISO TS 21412 is intended to help address this issue. It is also relevant to the process of qualification. specification and use of nano-obect-modified electrodes. The standardization of protocols to specify various types of nano-object-modified electrodes related to electrochemical detection will be used by most manufacturers or business owners of electrochemical electrodes products. This document focuses on the nano-object-assembled layer on electrodes by means of a solution process for electrochemical applications.
In ISO TS 21412, the specifications for a nano-obfrct constituting an assembled layer are provided, based on ISO/TS 12805, which describes the characteristics of manufactured nano-objects and their measurement methods (see Annex A). In addition, the characteristics of nano-object-assembled layer for enhanced clectrochemical blo-sensing applications and their measurement methods are provided in detail.
1 Scope
ISO TS 21412 specifies the characteristics to be measured or nano-object-assembled layers on electrodes by means of a solution process and of nano-obfrcts constituting the layers for electrochemical applications such as nano-biosensor or diagnosis applicatons. It also provides measurement methods for determining the characteristics.
It does not apply to:
— the requirements or nanostructures by top-down nanomanufacturing;
— the subsequent coating or materials such as biomaterials onto nano.object.assenibled layers;
— specific health and safety requirements during manufacturing;
— the experimental conditions of electrochemical sensing;
— the packaging, labelling, expiratory dates and transport of nano-object-enhanced electrochemical electrodes.
2 Normative references
The following documents are referred to in the text In such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated rererences, the latest edition of the rererenced document (including any amendments) applies.
ISO/TS 80004-2:2015, Nanotechnologies — Vocabulary — Part 2: Nono-objeas
ISO/TS 80004-4:2011, Nanotechnologies — Vocabulary — Port 4: Nanostructured materials
ISO/TS 80004-8:2013, Nonotechnologies — Vocabulary — Part 8: Nar,omanufacturing processes
3 Terms and definitions
For the purposes of ISO TS 21412, the terms and definitions given in ISO/TS 80004-2. ISO/TS 80004-4, ISO/TS 80004-8 and the following apply.
ISO and IEC maintain termmnological databases for use rn standardization at the rollowing addresses:
Note 2 to entry: The lower limit in this delinitlon (approximately 1 nm) is introduced to avoid single and small groups or atoms from being designated as nano.objects (32) or elements of nanostructures. which might be Implied by the absence of a lower limit.
(SOURCE: ISO/TS 80004-4:2011. 2.11
nano-oblect
material with one, two or three external dimensions in the nanoscale (11) Note Ito entry: Generk term for all discrete nanoscale obiects.
ISOURCE: ISO/TS 80004-4:2011, 2.21
3.3
particle
minute piece of matter with defined physical boundaries
[SOURCE: ISO/TS 80004-2:20)5,3.1. modified — The notes to entry have been deleted.]
3.4
agglomerate
collection of weakly bound particles (33), aggregates (15) or a mixture of the two where the resulting external surface area is similar to the sum of the surface areas of the individual components
Note Ito entry: the forces holding an agglomerate together are weak forces, for example van dec Waals forces or simple physical entanglement,
Note 2 to entry: Agglomerates are also termed secondary particles and the original source particles are termed primary particles.
ISOURCE: ISO/TS 80004-2:2015, 3.4, modified — weakly bound particles, aggregates or a mixture of the two has replaced weakly or medium strongly bound particles”.)
3.5
aggregate
purtrck (13) comprising strongly bonded or fused particles where the resulting external surface area is significantly smaller than the sum of surface areas of the individual components
Note ito entry: The forces holding an aggregate together are strong forces, for example covalent or ionic bonds, or those resulting from sintering or complex physical entanglement, or otlwrwlse combined former primary particles.
Note 2 to entry: Aggregates are also termed secondary particles and the original source particles are termed primary particles.
ISOURCE: ISO/TS 80004-2:2015, 3.51
nanoparticle
nano-objeci’ (32) with all three external dimensions n the nanoscale (3.1)
Note I to entry: lithe lengths of the longest to the shortest axes of the nano-objert diftec significantly (typically by more than three times), the terms ,,onoflbre (3.2) or nano plate (IU) are intended to be used instead of the term nanoparticle.
[SOURCE: ISO/TS 80004-4:2011,2.41
3.7
nanoHbre
nano-object (3.2) with two similar external dimensions in the nanoscale (3.1) and the third dimension significantly larger
Note ito entry: A nanolibre can be fletible or rigid.
Note 2 to entry: The two similar external dimensions are considered to differ In size by less thati three times and the signiticantly larger external dimension is considered to differ from the other two by more than three times, Note 3 to entry: The largest external dimension is not necessarily in the nanoscale.
ISOIJRCE: ISO/TS 80004-4:2011, 2.5, modified — The original note has been deleted and Notes 1, 2 and 3 to entry have been added.)
nanoplate
nono-objecl (3.2) with one external dimension in the rnrnoscale (Li) and the two other dimensions significantly larger
Note ito entry: The smallest external dimension is the thickness of the nanoplate.
Note 2 to entry The two significantly larger dimensions arc considered to differ from the nanoscale dimension by more than three times.
Note 3 to entry: The larger external dimensiotis are not necessarily In the nanoscale.
ISOURCE: ISO/TS 80004.4:2011, 2.61
3.9
top-down nanomanulacturlng
processes that create structures at the nortoscole (Ii.) from macroscopic objects
ISO11RCE: ISO/I’S 80004.8:2013.3.13)
4 CharacterIstics and measurement methods
4.1 General
This clause describes the characteristics of nano-object-assembled layers and constituting nanoobjects on flat substrate electrodes for electrochemical application. Because electrochemical biosensing requires an efficient electron transfer and a stable immobilization of blomolecules retaining their bioactivity. the characteristics given in 42 are selected for constituting nano-objects ii they logically and/or experimentally affect the high electron conducting pathway, high surface energy, high binding- site density and high functioning ability of the nano-objectIl to ll• From the perspective of the assembled layer. nano-objects may not be evenly assembled on a flat substrate electrode but produce surface topography throughout the whole area of the substrate. Because electrochemical biosensing requires an electrochemlcally active surface and a robust conducting layer, the characteristics in 43. such as mass per unit area and root mean square height, are selected to describe how thick and evenly the assembled layer is formed.
4.2 Characteristics of constituting nano-objects
The characteristics given in Table 1 shall be measured to describe the raw materials of nano.ob)ects constituting the nano-object-assembled layer. Measurement methods for the individual characteristics in Table I are described in Annex B. The measured value ot’the characteristics in Table I may be adopted from the material specifications by the provider of the nano-obect In suspension form If the intrinsic dimensional characteristics are unchanged after assembling.
As the method using surface-limited adsorption is not suitable for small mass of nano-obfrct on electrode. ECSA should be measured by the cyclic voltammetry method using a redox reaction to get a precise and accurate measured value. In the redox reaction, ECSA is determined by the calculation of Randles-Sevcik equation after obtaining a cyclic voltammogram using a redox couple In aqueous solution. The measurement procedure of a specific ECSA cia nano-obfrct-assembled layer is described in Annex D.
5 Test report
5.1 General
A user prefers specific synthetic properties of nano.obfrct.assembled layer according to their biosensing application and experimental conditions. To meet the preference of users, besides the characteristics of the nano-object-assembled layer, additional specifications are required to provide the information about the synthetic procedure of the nano-oblect-assembled layer such as substrate type and deposition process. All the characteristics and relevant information of the nano.obfrct. assembled layer shall be concisely arranged for effective delivery to stakeholders. This clause describes the formation and the order of specifications. An example of a test report is given in Annex F. The test report does not require to use the tables but may hst the items in three groups.
5.2 General Information on nano-object-modilled electrode
General information on the nano-obect-rnodified electrode given in Table 3 shall be provided to describe the synthetic procedure of the nano-obect-assembled layer in the first of all tables. This is because the characteristics of the nano-object-assembled layer could become meaningless when they are not matched to the preferences of the user’s application.