M plan apo

Two separate visualization systems were used, one for monitoring the fiber tip to cell distance and the other for cell targeting. The CTM was positioned at a right angle from the sample surface and above the electrospray and MS inlet orifice axis. Brightfield illumination was provided by a white LED with 6500 K color temperature (MCWHL5, Thorlabs, Newton, NJ, United States) with its intensity adjusted by a LED driver (LEDD1B, Thorlabs, Newton, NJ, United States). For uniform lighting, an aspheric condenser lens with a diffuser surface (ACL2520-DG15-A, Thorlabs, Newton, NJ, United States) was installed. Since the illumination was perpendicular to the sample surface and the camera, a 30:70 (reflection:transmission) beamsplitter (BSS10R, Thorlabs, Newton, NJ, United States) was inserted into the optical train. For cell targeting, a 20× infinity-corrected objective lens (M Plan Apo, Mitutoyo Co., Kanagawa, Japan) was combined with a 1× tube lens and a 4-megapixel monochrome CCD camera (4070-GE, Thorlabs, Newton, NJ, United States). A long working distance fiber-monitoring microscope (FMM) (AM4815ZTL, Dino-lite, Torrance, CA, United States) with an extended magnification range (5× to 140×) was positioned at a 20° elevation angle to the sample surface.

To investigate optical properties of TiO₂ and AlOOH coatings, ink was printed on polished glass surface (microscope slides 26 mm × 76 mm, Paul Marienfeld, Germany) using Canon IP2480 inkjet printer. After applying, the produced sol was dried at 60 °C in the air for 15 minutes to form a thin layer of TiO₂.
Then, optical reflection measurement of TiO₂ films at normal incidence was carried out to obtain refractive indices. For this experiment the confocal optical scheme was arranged Figure S2. The incident unpolarized light from a halogen lamp (HL-2000-FHSA) was focused on the film surface through a 50x microscope objective (Mitutoyo M Plan APO, NA 0.55). Reflected light was collected through the same objective and then analyzed by a spectrometer (HORIBA LabRam HR) with a cooled CCD camera (Andor DU 420A-OE) and a 150 g/mm diffraction grating. The obtained spectra were normalized by the known spectrum of the halogen lamp. The reflectance spectra from different points of the film allowed us to estimate the error for refractive indices at various wavelengths.

(Photo)electrochemical
experiments were performed using either a CH Instruments 760E or a
HEKA ELP-1 bipotentiostat. All measurements were performed in a 30
mL electrochemical cell with a borosilicate glass window in a three-electrode
configuration. A saturated calomel electrode (SCE) and a Pt wire were
used as the reference and counter electrodes, respectively. Illumination
of the semiconductor was performed using a white light LED from AM
Scope with a calibrated intensity of 85 mW cm^–2.
For varied power experiments, the semiconductor was illuminated with
a 530 nm (2.3 eV) fiber-coupled LED (M530F2) coupled to a 550 μm
diameter fiber optic cable (MHP550L02, Thorlabs; 0.22 NA), a F240SMA-532
collimator, and a 20× LWD objective (Mitutoyo M Plan Apo; 0.42
NA). The LED intensity was controlled using a constant-current LED
driver from Thorlabs (UPLED) controlled using upSERIES software. A
calibration curve relating the LED driver current and LED intensity
was created by measuring the intensity using a USB power meter from
Thorlabs (PM16-122) and is shown in Figure S6 in the Supporting Information. Prior to each set of experiments,
a one-point power calibration was performed. All optical components
were purchased from Thorlabs and housed inside a custom-built dark
box to eliminate ambient light.