MONITORING Au NP AND NANOCLUSTERS VIA HIGHRESOLUTION CONTINUUM SOURCE GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

Recent investigations demonstrate that high-resolution continuum source graphite
furnace atomic absorption spectrometry (HR CS GFAAS) can provide relevant
information for nanoparticle (NP) research, particularly for Ag NPs.1
However, that is not the only analyte for which this technique may be useful. This work
investigates the possibility of obtaining information on the chemical form (ionic or as Au
nanoparticles (NPs)) in which Au is found in solutions by HR CS GFAAS, without the
need to use any additional separation step or technique. It is demonstrated that proper
optimization of the temperature program, using a very low heating ramp during the
atomization step and in the absence of chemical modifiers, enables a fast and simple
screening to be performed, since the signal profiles obtained for solutions/suspensions of
ionic Au and AuNPs are very dissimilar. Moreover, in the case of finding NPs, it is
possible to estimate the average particle size, because this parameter appears to be directly
related with the time of appearance of the maximum peak height.
Furthermore, in the case of Au nanoclusters, it seems also possible to establish if the NPs
are linked to target biomolecules, or else they are free in the solution, which offers
significant advantages for current sensor research based on the use of AuNPs.