Mohammad Reza Ganjali talks
with ScienceWatch.com and answers a few questions
about this month's Fast Breaking Paper in the field of
Engineering.
Article Title: Lanthanide recognition: an asymetric
erbium microsensor based on a hydrazone
derivative
Authors: Faridbod,
F;Ganjali,
MR;Larijani, B;Norouzi, P;Riahi, S;Mirnaghi,
FS
Journal: SENSORS
Volume: 7
Issue: 12
Page: 3119-3135
Year: DEC 2007
* Univ Tehran, Fac Chem, Ctr Excellence Electrochem,
Tehran, Iran.
* Univ Tehran, Fac Chem, Ctr Excellence Electrochem,
Tehran, Iran.
(addresses have been truncated)
Why do you think your paper is highly
cited?
This work is the first report on a PVC membrane microsensor for
potentiometric determination of erbium ions in the world. Erbium is one of
the lanthanoid members and their selective determination is one of the most
challenging areas of research. Finding a suitable ionophore which is able
to form a selective complex with one of the lanthanoid cations among the
other ones has a significant effect in the construction of ion-selective
electrodes (ISE).
Also, since this paper is published in an open access journal (Sensors,
MDPI), the full text of this new research article is easily accessible
to many researchers in the world. Fortunately, I have a curious and
diligent research team in my laboratory, where each person is an expert
focusing on one of the fields of chemistry—analytical, electro,
chemometrics, organic, and inorganic synthesis. In my opinion, good
teamwork is the key for development in the new and ever-changing
professional scientific world.
Does it describe a new discovery, methodology, or synthesis of
knowledge?
"...because of the increasing
industrial use of lanthanum compounds, along
with their enhanced discharge and
simultaneously useful and harmful biological
activity, monitoring of trace amounts of
lanthanoid has recently been of increasing
concern."
This work describes the first asymmetric potentiometric membrane
microsensor. The ionophore which is used in this work was synthesized by
our team.
Would you summarize the significance of your paper in
layman’s terms?
The main global problem in the field of ISE was finding a selective sensor
for lanthanides. Researchers around the world had tried to construct a
selective sensor for lanthanide ions using the aid of ionophores having
cavities like crown ethers, but these were not quite successful.
The only way to design an ISE for lanthanide ions is by using ionophores
having a semi-cavity, heteroatoms (mostly S and N as donor atoms), and high
flexibility. Such an ionophore can easily form a template with reference to
the size of the cation.
Furthermore, this particular ionophore is able to form a stronger complex
with one of the cations than with the other ones. This phenomenon can be
attributed to the type, number, and site of its donor atoms, its
flexibility as well as the size and charge density of the cation.
How did you become involved in this research, and were there any
problems along the way?
I have worked on potentiometric sensors for 14 years and I'm the
corresponding author of this research article. My research is mainly
focused on lanthanide sensors. Up to now, nearly 70% of the lanthanoid
sensors in the world have been reported by our research team.
Where do you see your research leading in the future?
The interest in lanthanoid interaction with biochemical molecules arises
because they have shown some therapeutic properties during the past decade
which can also be used as probes to study the interactions between calcium
ions (Ca2+) with biologically important molecules.
Thus, because of the increasing industrial use of lanthanum compounds,
along with their enhanced discharge and simultaneously useful and harmful
biological activity, monitoring of trace amounts of lanthanoid has recently
been of increasing concern. There are several main methods for trace-amount
monitoring of lanthanoid ions in solutions. These include X-ray
fluorescence spectrometry, inductively coupled plasma-atomic emission
spectrometry (ICP-AES), isotope dilution mass spectrometry (IDMS), and
neutron activation analysis.
These methods are either time consuming, involving multiple sample
manipulations, or simply too expensive for most analytical laboratories.
Potentiometric electrodes offer several advantages, such as their quickness
and ease of preparations and procedures, simple instrumentation, relatively
fast responses, very low detection limits, wide dynamic ranges, reasonable
selectivity, portability, and low cost.
This has led to an increase in the number of available sensors and
microsensors over the past few years. In addition, the miniaturization of
the working electrode for the in vivo or in vitro
determinations of the analyte, or for use in the flow injection system has
recently become another interesting area of research.
Professor Mohammad Reza Ganjali
Professor in Analytical Chemistry
Center of Excellence in Electrochemistry
University of Tehran
Tehran, Iran