part of this chapter will be devoted to bioelectrodes based on the combination
of nanometal species and enzymes, which are devices that are expected to have
many future applications within the field of medicine. These bioelectrodes could,
for example, be integrated into biofuel cells that are supposed to power different
medical implants or biosensors [5, 6]. The final part of this chapter will be dedicated
to bacteria that are able to reduce metal salts into metal NPs, and here we will give
examples on how these bacteria can be exploited for the design of biometallic
whole cell systems. The research in such “living bioinorganic hybrids” constitutes
a very exciting frontier in catalysis, and as we will show in this part, they could very
well be harnessed for applications in the fields of organic synthesis, environmental
remediation, and energy research [7].
2 Nano Meets Bio in Organic Synthesis
Nature has always been a major source of inspiration and fascination to chemists.
Despite the impressive progress that has been made within the field of organic
chemistry during the past century, we are still in many regards far behind Nature.
For example, when it comes to the practice of executing synthetic sequences, we
still have a lot to learn from the natural systems. In contrast to our synthetic
sequences that are often done in a stepwise fashion, and which require isolation
and purification of each chemical intermediate, Nature makes use of well-organized
multienzymatic systems in which each chemical step is coupled to the next, to
enable more efficient and selective cascade processes [8]. Furthermore, many of
the enzymes involved in these intricate cascades are equipped with metal-containing
cofactors that help them to carry out chemical transformations that are not possible
to achieve with the chemistry of the amino acids. Thus, these so-called
metalloenzymes are often used by biological systems in highly challenging chemical
processes, such as photosynthesis, respiration, and nitrogen fixation [9–11].
With the ambition to construct reaction sequences that are as well-orchestrated
as those seen in Nature, chemists have explored many different strategies for
combining different kinds of catalytic processes, in order to create more efficient
cascade reactions. One approach that has proven to be particularly fruitful has
been the combination of transition metal catalysis and enzyme catalysis [12].
Here, the rapidly developing nanotechnology field has been one the most important
driving forces, as it has continuously provided chemists with new and intriguing
ways of bringing metal nanocatalysts and enzymes together. Especially interesting
are those approaches that allow for the conservation of the catalytic functions of
both entities. This is in many cases not possible to achieve with the conventional
“artificial metalloenzyme” design approach [3, 13], where insertion of a catalytically
active metal center into the active site of the enzyme often abolishes the native
catalytic function of the latter.
In this part, different strategies for bringing metal NPs and enzymes together
for applications in organic synthesis will be highlighted. These examples generally
Nanocatalysis Meets Biology
245
of nanometal species and enzymes, which are devices that are expected to have
many future applications within the field of medicine. These bioelectrodes could,
for example, be integrated into biofuel cells that are supposed to power different
medical implants or biosensors [5, 6]. The final part of this chapter will be dedicated
to bacteria that are able to reduce metal salts into metal NPs, and here we will give
examples on how these bacteria can be exploited for the design of biometallic
whole cell systems. The research in such “living bioinorganic hybrids” constitutes
a very exciting frontier in catalysis, and as we will show in this part, they could very
well be harnessed for applications in the fields of organic synthesis, environmental
remediation, and energy research [7].
2 Nano Meets Bio in Organic Synthesis
Nature has always been a major source of inspiration and fascination to chemists.
Despite the impressive progress that has been made within the field of organic
chemistry during the past century, we are still in many regards far behind Nature.
For example, when it comes to the practice of executing synthetic sequences, we
still have a lot to learn from the natural systems. In contrast to our synthetic
sequences that are often done in a stepwise fashion, and which require isolation
and purification of each chemical intermediate, Nature makes use of well-organized
multienzymatic systems in which each chemical step is coupled to the next, to
enable more efficient and selective cascade processes [8]. Furthermore, many of
the enzymes involved in these intricate cascades are equipped with metal-containing
cofactors that help them to carry out chemical transformations that are not possible
to achieve with the chemistry of the amino acids. Thus, these so-called
metalloenzymes are often used by biological systems in highly challenging chemical
processes, such as photosynthesis, respiration, and nitrogen fixation [9–11].
With the ambition to construct reaction sequences that are as well-orchestrated
as those seen in Nature, chemists have explored many different strategies for
combining different kinds of catalytic processes, in order to create more efficient
cascade reactions. One approach that has proven to be particularly fruitful has
been the combination of transition metal catalysis and enzyme catalysis [12].
Here, the rapidly developing nanotechnology field has been one the most important
driving forces, as it has continuously provided chemists with new and intriguing
ways of bringing metal nanocatalysts and enzymes together. Especially interesting
are those approaches that allow for the conservation of the catalytic functions of
both entities. This is in many cases not possible to achieve with the conventional
“artificial metalloenzyme” design approach [3, 13], where insertion of a catalytically
active metal center into the active site of the enzyme often abolishes the native
catalytic function of the latter.
In this part, different strategies for bringing metal NPs and enzymes together
for applications in organic synthesis will be highlighted. These examples generally
Nanocatalysis Meets Biology
245