ISO/TS 21412:2020

TECHNICAL ISO/TS
SPECIFICATION 21412
First edition
2020-04
Nanotechnologies — Nano-object-
assembled layers for electrochemical
bio-sensing applications —
Specification of characteristics and
measurement methods
Nanotechnologies — Couches nanostructurées pour des applications
de biodétection électrochimique — Spécification des caractéristiques
et des méthodes de mesure
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Characteristics and measurement methods . 3
4.1 General . 3
4.2 Characteristics of constituting nano-objects . 3
4.3 Characteristics of nano-object-assembled layer . 4
4.3.1 General. 4
4.3.2 Mass per unit area . 4
4.3.3 Root mean square height . 5
4.3.4 Specific electrochemically active surface area (ECSA) . 5
5 Test report . 6
5.1 General . 6
5.2 General information on nano-object-modified electrode . 6
5.3 Measurement results of characteristics . 6
Annex A (informative) Value chain of nano-object-modified electrochemical electrode .8
Annex B (informative) Measurement methods for characteristics . 9
Annex C (informative) Calculation of mass per unit area using drop-casting method .13
Annex D (informative) Measurement of specific ECSA of nano-object-assembled layer .14
Annex E (informative) General information on nano-object-modified electrode .15
Annex F (informative) Example of test report .18
Bibliography .20
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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This document was prepared by Technical Committee ISO/TC 229, Nanotechnologies.
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iv © ISO 2020 – All rights reserved

Introduction
Electrochemical electrodes can exhibit nano-enhanced performance after the deposition of nano-
objects 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 nano-
biosensors.  Nano-biosensor sensitivity, selectivity and reliability can be enhanced with specific nano-
[22][25][26] [24] [37] [38]
objects, e.g. gold nanoparticles , carbon nanotubes , CuS nanorods and silver or
[23]
palladium nanoplates .
Currently, most of the nano-enhanced 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. Fabricators are offering nano-enhanced
electrodes to instrument manufacturers as a platform to add additional coatings for specific sensing
applications. This document supports the development of material specifications for the transaction
between electrode fabrications and instrument manufacturers to allow the purchase of electrodes with
predictable performance.
This document is intended to help address this issue. It is also relevant to the process of qualification,
specification and use of nano-object-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 this document, the specifications for a nano-object 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 electrochemical bio-sensing applications and their measurement methods are provided
in detail.
TECHNICAL SPECIFICATION ISO/TS 21412:2020(E)
Nanotechnologies — Nano-object-assembled layers for
electrochemical bio-sensing applications — Specification
of characteristics and measurement methods
1 Scope
This document specifies the characteristics to be measured of nano-object-assembled layers on
electrodes by means of a solution process and of nano-objects constituting the layers for electrochemical
applications such as nano-biosensor or diagnosis applications. It also provides measurement methods
for determining the characteristics.
It does not apply to:
— the requirements of nanostructures by top-down nanomanufacturing;
— the subsequent coating of materials such as biomaterials onto nano-object-assembled 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 references, the latest edition of the referenced document (including any amendments) applies.
ISO/TS 80004-2:2015, Nanotechnologies — Vocabulary — Part 2: Nano-objects
ISO/TS 80004-4:2011, Nanotechnologies — Vocabulary — Part 4: Nanostructured materials
ISO/TS 80004-8:2013, Nanotechnologies — Vocabulary — Part 8: Nanomanufacturing processes
3 Terms and definitions
For the purposes of this document, 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 terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
nanoscale
size range from approximately 1 nm to 100 nm
Note 1 to entry: Properties that are not extrapolations from a larger size will typically, but not exclusively, be
exhibited in this size range. For such properties the size limits are considered approximate.
Note 2 to entry: The lower limit in this definition (approximately 1 nm) is introduced to avoid single and small
groups of atoms from being designated as nano-objects (3.2) or elements of nanostructures, which might be
implied by the absence of a lower limit.
[SOURCE: ISO/TS 80004-4:2011, 2.1]
3.2
nano-object
material with one, two or three external dimensions in the nanoscale (3.1)
Note 1 to entry: Generic term for all discrete nanoscale objects.
[SOURCE: ISO/TS 80004-4:2011, 2.2]
3.3
particle
minute piece of matter with defined physical boundaries
[SOURCE: ISO/TS 80004-2:2015, 3.1, modified — The notes to entry have been deleted.]
3.4
agglomerate
collection of weakly bound particles (3.3), aggregates (3.5) 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 1 to entry: The forces holding an agglomerate together are weak forces, for example van der 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.
[SOURCE: 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
particle (3.3) 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 1 to 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 otherwise combined former primary
particles.
Note 2 to entry: Aggregates are also termed secondary particles and the original source particles are termed
primary particles.
[SOURCE: ISO/TS 80004-2:2015, 3.5]
3.6
nanoparticle
nano-object (3.2) with all three external dimensions in the nanoscale (3.1)
Note 1 to entry: If the lengths of the longest to the shortest axes of the nano-object differ significantly (typically
by more than three times), the terms nanofibre (3.7) or nanoplate (3.8) are intended to be used instead of the
term nanoparticle.
[SOURCE: ISO/TS 80004-4:2011, 2.4]
3.7
nanofibre
nano-object (3.2) with two similar external dimensions in the nanoscale (3.1) and the third dimension
significantly larger
Note 1 to entry: A
...